patch, 5 partsscalar: implement the subcommand "diagnose"

contrib/scalar/scalar.c, contrib/scalar/scalar.txt, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 1ce9c2b00e8..13f2b0f4d5a 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -259,6 +259,108 @@ static int unregister_dir(void)
 	return res;
 }
 
+static int stage(const char *git_dir, struct strbuf *buf, const char *path)
+{
+	struct strbuf cacheinfo = STRBUF_INIT;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	int res;
+
+	strbuf_addstr(&cacheinfo, "100644,");
+
+	cp.git_cmd = 1;
+	strvec_pushl(&cp.args, "--git-dir", git_dir,
+		     "hash-object", "-w", "--stdin", NULL);
+	res = pipe_command(&cp, buf->buf, buf->len, &cacheinfo, 256, NULL, 0);
+	if (!res) {
+		strbuf_rtrim(&cacheinfo);
+		strbuf_addch(&cacheinfo, ',');
+		/* We cannot stage `.git`, use `_git` instead. */
+		if (starts_with(path, ".git/"))
+			strbuf_addf(&cacheinfo, "_%s", path + 1);
+		else
+			strbuf_addstr(&cacheinfo, path);
+
+		child_process_init(&cp);
+		cp.git_cmd = 1;
+		strvec_pushl(&cp.args, "--git-dir", git_dir,
+			     "update-index", "--add", "--cacheinfo",
+			     cacheinfo.buf, NULL);
+		res = run_command(&cp);
+	}
+
+	strbuf_release(&cacheinfo);
+	return res;
+}
+
+static int stage_file(const char *git_dir, const char *path)
+{
+	struct strbuf buf = STRBUF_INIT;
+	int res;
+
+	if (strbuf_read_file(&buf, path, 0) < 0)
+		return error(_("could not read '%s'"), path);
+
+	res = stage(git_dir, &buf, path);
+
+	strbuf_release(&buf);
+	return res;
+}
+
+static int stage_directory(const char *git_dir, const char *path, int recurse)
+{
+	int at_root = !*path;
+	DIR *dir = opendir(at_root ? "." : path);
+	struct dirent *e;
+	struct strbuf buf = STRBUF_INIT;
+	size_t len;
+	int res = 0;
+
+	if (!dir)
+		return error(_("could not open directory '%s'"), path);
+
+	if (!at_root)
+		strbuf_addf(&buf, "%s/", path);
+	len = buf.len;
+
+	while (!res && (e = readdir(dir))) {
+		if (!strcmp(".", e->d_name) || !strcmp("..", e->d_name))
+			continue;
+
+		strbuf_setlen(&buf, len);
+		strbuf_addstr(&buf, e->d_name);
+
+		if ((e->d_type == DT_REG && stage_file(git_dir, buf.buf)) ||
+		    (e->d_type == DT_DIR && recurse &&
+		     stage_directory(git_dir, buf.buf, recurse)))
+			res = -1;
+	}
+
+	closedir(dir);
+	strbuf_release(&buf);
+	return res;
+}
+
+static int index_to_zip(const char *git_dir)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+	struct strbuf oid = STRBUF_INIT;
+
+	cp.git_cmd = 1;
+	strvec_pushl(&cp.args, "--git-dir", git_dir, "write-tree", NULL);
+	if (pipe_command(&cp, NULL, 0, &oid, the_hash_algo->hexsz + 1,
+			 NULL, 0))
+		return error(_("could not write temporary tree object"));
+
+	strbuf_rtrim(&oid);
+	child_process_init(&cp);
+	cp.git_cmd = 1;
+	strvec_pushl(&cp.args, "--git-dir", git_dir, "archive", "-o", NULL);
+	strvec_pushf(&cp.args, "%s.zip", git_dir);
+	strvec_pushl(&cp.args, oid.buf, "--", NULL);
+	strbuf_release(&oid);
+	return run_command(&cp);
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -499,6 +601,73 @@ cleanup:
 	return res;
 }
 
+static int cmd_diagnose(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		N_("scalar diagnose [<enlistment>]"),
+		NULL
+	};
+	struct strbuf tmp_dir = STRBUF_INIT;
+	time_t now = time(NULL);
+	struct tm tm;
+	struct strbuf path = STRBUF_INIT, buf = STRBUF_INIT;
+	int res = 0;
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	setup_enlistment_directory(argc, argv, usage, options, &buf);
+
+	strbuf_addstr(&buf, "/.scalarDiagnostics/scalar_");
+	strbuf_addftime(&buf, "%Y%m%d_%H%M%S", localtime_r(&now, &tm), 0, 0);
+	if (run_git("init", "-q", "-b", "dummy", "--bare", buf.buf, NULL)) {
+		res = error(_("could not initialize temporary repository: %s"),
+			    buf.buf);
+		goto diagnose_cleanup;
+	}
+	strbuf_realpath(&tmp_dir, buf.buf, 1);
+
+	strbuf_reset(&buf);
+	strbuf_addf(&buf, "Collecting diagnostic info into temp folder %s\n\n",
+		    tmp_dir.buf);
+
+	get_version_info(&buf, 1);
+
+	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	fwrite(buf.buf, buf.len, 1, stdout);
+
+	if ((res = stage(tmp_dir.buf, &buf, "diagnostics.log")))
+		goto diagnose_cleanup;
+
+	if ((res = stage_directory(tmp_dir.buf, ".git", 0)) ||
+	    (res = stage_directory(tmp_dir.buf, ".git/hooks", 0)) ||
+	    (res = stage_directory(tmp_dir.buf, ".git/info", 0)) ||
+	    (res = stage_directory(tmp_dir.buf, ".git/logs", 1)) ||
+	    (res = stage_directory(tmp_dir.buf, ".git/objects/info", 0)))
+		goto diagnose_cleanup;
+
+	res = index_to_zip(tmp_dir.buf);
+
+	if (!res)
+		res = remove_dir_recursively(&tmp_dir, 0);
+
+	if (!res)
+		printf("\n"
+		       "Diagnostics complete.\n"
+		       "All of the gathered info is captured in '%s.zip'\n",
+		       tmp_dir.buf);
+
+diagnose_cleanup:
+	strbuf_release(&tmp_dir);
+	strbuf_release(&path);
+	strbuf_release(&buf);
+
+	return res;
+}
+
 static int cmd_list(int argc, const char **argv)
 {
 	if (argc != 1)
@@ -800,6 +969,7 @@ static struct {
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
 	{ "version", cmd_version },
+	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
 };
 
diff --git a/contrib/scalar/scalar.txt b/contrib/scalar/scalar.txt
index f416d637289..22583fe046e 100644
--- a/contrib/scalar/scalar.txt
+++ b/contrib/scalar/scalar.txt
@@ -14,6 +14,7 @@ scalar register [<enlistment>]
 scalar unregister [<enlistment>]
 scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
 scalar reconfigure [ --all | <enlistment> ]
+scalar diagnose [<enlistment>]
 scalar delete <enlistment>
 
 DESCRIPTION
@@ -129,6 +130,17 @@ reconfigure the enlistment.
 With the `--all` option, all enlistments currently registered with Scalar
 will be reconfigured. Use this option after each Scalar upgrade.
 
+Diagnose
+~~~~~~~~
+
+diagnose [<enlistment>]::
+    When reporting issues with Scalar, it is often helpful to provide the
+    information gathered by this command, including logs and certain
+    statistics describing the data shape of the current enlistment.
++
+The output of this command is a `.zip` file that is written into
+a directory adjacent to the worktree in the `src` directory.
+
 Delete
 ~~~~~~
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 2e1502ad45e..ecd06e207c2 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -65,6 +65,19 @@ test_expect_success 'scalar clone' '
 	)
 '
 
+SQ="'"
+test_expect_success UNZIP 'scalar diagnose' '
+	scalar diagnose cloned >out &&
+	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
+	zip_path=$(cat zip_path) &&
+	test -n "$zip_path" &&
+	unzip -v "$zip_path" &&
+	folder=${zip_path%.zip} &&
+	test_path_is_missing "$folder" &&
+	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out
+'
+
 test_expect_success 'scalar reconfigure' '
 	git init one/src &&
 	scalar register one &&

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 13f2b0f4d5a..e26fb2fc018 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -361,6 +361,58 @@ static int index_to_zip(const char *git_dir)
 	return run_command(&cp);
 }
 
+#ifndef WIN32
+#include <sys/statvfs.h>
+#endif
+
+static int get_disk_info(struct strbuf *out)
+{
+#ifdef WIN32
+	struct strbuf buf = STRBUF_INIT;
+	char volume_name[MAX_PATH], fs_name[MAX_PATH];
+	DWORD serial_number, component_length, flags;
+	ULARGE_INTEGER avail2caller, total, avail;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (!GetDiskFreeSpaceExA(buf.buf, &avail2caller, &total, &avail)) {
+		error(_("could not determine free disk size for '%s'"),
+		      buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_setlen(&buf, offset_1st_component(buf.buf));
+	if (!GetVolumeInformationA(buf.buf, volume_name, sizeof(volume_name),
+				   &serial_number, &component_length, &flags,
+				   fs_name, sizeof(fs_name))) {
+		error(_("could not get info for '%s'"), buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, avail2caller.QuadPart);
+	strbuf_addch(out, '\n');
+	strbuf_release(&buf);
+#else
+	struct strbuf buf = STRBUF_INIT;
+	struct statvfs stat;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (statvfs(buf.buf, &stat) < 0) {
+		error_errno(_("could not determine free disk size for '%s'"),
+			    buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, st_mult(stat.f_bsize, stat.f_bavail));
+	strbuf_addf(out, " (mount flags 0x%lx)\n", stat.f_flag);
+	strbuf_release(&buf);
+#endif
+	return 0;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -637,6 +689,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	get_version_info(&buf, 1);
 
 	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	get_disk_info(&buf);
 	fwrite(buf.buf, buf.len, 1, stdout);
 
 	if ((res = stage(tmp_dir.buf, &buf, "diagnostics.log")))

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index e26fb2fc018..690933ffdf3 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -653,6 +653,39 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	struct stat e_stat;
+	struct strbuf file_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Contents of ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&file_path, path);
+	strbuf_addch(&file_path, '/');
+	base_path_len = file_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG) {
+			strbuf_setlen(&file_path, base_path_len);
+			strbuf_addstr(&file_path, e->d_name);
+			if (!stat(file_path.buf, &e_stat))
+				strbuf_addf(buf, "%-70s %16"PRIuMAX"\n",
+					    e->d_name,
+					    (uintmax_t)e_stat.st_size);
+		}
+
+	strbuf_release(&file_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -695,6 +728,12 @@ static int cmd_diagnose(int argc, const char **argv)
 	if ((res = stage(tmp_dir.buf, &buf, "diagnostics.log")))
 		goto diagnose_cleanup;
 
+	strbuf_reset(&buf);
+	dir_file_stats(&buf, ".git/objects/pack");
+
+	if ((res = stage(tmp_dir.buf, &buf, "packs-local.txt")))
+		goto diagnose_cleanup;
+
 	if ((res = stage_directory(tmp_dir.buf, ".git", 0)) ||
 	    (res = stage_directory(tmp_dir.buf, ".git/hooks", 0)) ||
 	    (res = stage_directory(tmp_dir.buf, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index ecd06e207c2..b1745851e31 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -75,6 +75,8 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
 	test_file_not_empty out
 '
 

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 690933ffdf3..c0ad4948215 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -686,6 +686,60 @@ static void dir_file_stats(struct strbuf *buf, const char *path)
 	closedir(dir);
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -734,6 +788,12 @@ static int cmd_diagnose(int argc, const char **argv)
 	if ((res = stage(tmp_dir.buf, &buf, "packs-local.txt")))
 		goto diagnose_cleanup;
 
+	strbuf_reset(&buf);
+	loose_objs_stats(&buf, ".git/objects");
+
+	if ((res = stage(tmp_dir.buf, &buf, "objects-local.txt")))
+		goto diagnose_cleanup;
+
 	if ((res = stage_directory(tmp_dir.buf, ".git", 0)) ||
 	    (res = stage_directory(tmp_dir.buf, ".git/hooks", 0)) ||
 	    (res = stage_directory(tmp_dir.buf, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index b1745851e31..f2ec156d819 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -77,6 +77,8 @@ test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
+	test_file_not_empty out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
 	test_file_not_empty out
 '
 

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index c0ad4948215..224329f38f5 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -259,12 +259,26 @@ static int unregister_dir(void)
 	return res;
 }
 
+static void spinner(void)
+{
+	static const char whee[] = "|\010/\010-\010\\\010", *next = whee;
+
+	if (!next)
+		return;
+	if (write(2, next, 2) < 0)
+		next = NULL;
+	else
+		next = next[2] ? next + 2 : whee;
+}
+
 static int stage(const char *git_dir, struct strbuf *buf, const char *path)
 {
 	struct strbuf cacheinfo = STRBUF_INIT;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	int res;
 
+	spinner();
+
 	strbuf_addstr(&cacheinfo, "100644,");
 
 	cp.git_cmd = 1;

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 1ce9c2b00e8..00dcd4b50ef 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -43,9 +43,11 @@ static void setup_enlistment_directory(int argc, const char **argv,
 		usage_with_options(usagestr, options);
 
 	/* find the worktree, determine its corresponding root */
-	if (argc == 1)
+	if (argc == 1) {
 		strbuf_add_absolute_path(&path, argv[0]);
-	else if (strbuf_getcwd(&path) < 0)
+		if (!is_directory(path.buf))
+			die(_("'%s' does not exist"), path.buf);
+	} else if (strbuf_getcwd(&path) < 0)
 		die(_("need a working directory"));
 
 	strbuf_trim_trailing_dir_sep(&path);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 2e1502ad45e..9d83fdf25e8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -85,4 +85,9 @@ test_expect_success 'scalar delete with enlistment' '
 	test_path_is_missing cloned
 '
 
+test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
+	! scalar run config cloned 2>err &&
+	grep "cloned. does not exist" err
+'
+
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a7834..1b52a0a65a1 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -61,6 +61,17 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 
+--add-file-with-content=<path>:<content>::
+	Add the specified contents to the archive.  Can be repeated to add
+	multiple files.  The path of the file in the archive is built
+	by concatenating the value for `--prefix` (if any) and the
+	basename of <file>.
++
+The `<path>` cannot contain any colon, the file mode is limited to
+a regular file, and the option may be subject platform-dependent
+command-line limits. For non-trivial cases, write an untracked file
+and use `--add-file` instead.
+
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
 	as well (see <<ATTRIBUTES>>).
diff --git a/archive.c b/archive.c
index a3bbb091256..172efd690c3 100644
--- a/archive.c
+++ b/archive.c
@@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 struct extra_file_info {
 	char *base;
 	struct stat stat;
+	void *content;
 };
 
 int write_archive_entries(struct archiver_args *args,
@@ -337,7 +338,13 @@ int write_archive_entries(struct archiver_args *args,
 		strbuf_addstr(&path_in_archive, basename(path));
 
 		strbuf_reset(&content);
-		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
+		if (info->content)
+			err = write_entry(args, &fake_oid, path_in_archive.buf,
+					  path_in_archive.len,
+					  info->stat.st_mode,
+					  info->content, info->stat.st_size);
+		else if (strbuf_read_file(&content, path,
+					  info->stat.st_size) < 0)
 			err = error_errno(_("could not read '%s'"), path);
 		else
 			err = write_entry(args, &fake_oid, path_in_archive.buf,
@@ -493,6 +500,7 @@ static void extra_file_info_clear(void *util, const char *str)
 {
 	struct extra_file_info *info = util;
 	free(info->base);
+	free(info->content);
 	free(info);
 }
 
@@ -514,14 +522,38 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	if (!arg)
 		return -1;
 
-	path = prefix_filename(args->prefix, arg);
-	item = string_list_append_nodup(&args->extra_files, path);
-	item->util = info = xmalloc(sizeof(*info));
+	info = xmalloc(sizeof(*info));
 	info->base = xstrdup_or_null(base);
-	if (stat(path, &info->stat))
-		die(_("File not found: %s"), path);
-	if (!S_ISREG(info->stat.st_mode))
-		die(_("Not a regular file: %s"), path);
+
+	if (strcmp(opt->long_name, "add-file-with-content")) {
+		path = prefix_filename(args->prefix, arg);
+		if (stat(path, &info->stat))
+			die(_("File not found: %s"), path);
+		if (!S_ISREG(info->stat.st_mode))
+			die(_("Not a regular file: %s"), path);
+		info->content = NULL; /* read the file later */
+	} else {
+		const char *colon = strchr(arg, ':');
+		char *p;
+
+		if (!colon)
+			die(_("missing colon: '%s'"), arg);
+
+		p = xstrndup(arg, colon - arg);
+		if (!args->prefix)
+			path = p;
+		else {
+			path = prefix_filename(args->prefix, p);
+			free(p);
+		}
+		memset(&info->stat, 0, sizeof(info->stat));
+		info->stat.st_mode = S_IFREG | 0644;
+		info->content = xstrdup(colon + 1);
+		info->stat.st_size = strlen(info->content);
+	}
+	item = string_list_append_nodup(&args->extra_files, path);
+	item->util = info;
+
 	return 0;
 }
 
@@ -554,6 +586,9 @@ static int parse_archive_args(int argc, const char **argv,
 		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
 		  N_("add untracked file to archive"), 0, add_file_cb,
 		  (intptr_t)&base },
+		{ OPTION_CALLBACK, 0, "add-file-with-content", args,
+		  N_("file"), N_("add untracked file to archive"), 0,
+		  add_file_cb, (intptr_t)&base },
 		OPT_STRING('o', "output", &output, N_("file"),
 			N_("write the archive to this file")),
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 1e6d18b140e..8ff1257f1a0 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -206,6 +206,18 @@ test_expect_success 'git archive --format=zip --add-file' '
 check_zip with_untracked
 check_added with_untracked untracked untracked
 
+test_expect_success UNZIP 'git archive --format=zip --add-file-with-content' '
+	git archive --format=zip >with_file_with_content.zip \
+		--add-file-with-content=hello:world $EMPTY_TREE &&
+	test_when_finished "rm -rf tmp-unpack" &&
+	mkdir tmp-unpack && (
+		cd tmp-unpack &&
+		"$GIT_UNZIP" ../with_file_with_content.zip &&
+		test_path_is_file hello &&
+		test world = $(cat hello)
+	)
+'
+
 test_expect_success 'git archive --format=zip --add-file twice' '
 	echo untracked >untracked &&
 	git archive --format=zip --prefix=one/ --add-file=untracked \

tempfile.c, tempfile.h

diff --git a/tempfile.c b/tempfile.c
index 94aa18f3f7..2024c82691 100644
--- a/tempfile.c
+++ b/tempfile.c
@@ -56,6 +56,20 @@

 static VOLATILE_LIST_HEAD(tempfile_list);

+static void remove_template_directory(struct tempfile *tempfile,
+				      int in_signal_handler)
+{
+	if (tempfile->directorylen > 0 &&
+	    tempfile->directorylen < tempfile->filename.len &&
+	    tempfile->filename.buf[tempfile->directorylen] == '/') {
+		strbuf_setlen(&tempfile->filename, tempfile->directorylen);
+		if (in_signal_handler)
+			rmdir(tempfile->filename.buf);
+		else
+			rmdir_or_warn(tempfile->filename.buf);
+	}
+}
+
 static void remove_tempfiles(int in_signal_handler)
 {
 	pid_t me = getpid();
@@ -74,6 +88,7 @@ static void remove_tempfiles(int in_signal_handler)
 			unlink(p->filename.buf);
 		else
 			unlink_or_warn(p->filename.buf);
+		remove_template_directory(p, in_signal_handler);

 		p->active = 0;
 	}
@@ -100,6 +115,7 @@ static struct tempfile *new_tempfile(void)
 	tempfile->owner = 0;
 	INIT_LIST_HEAD(&tempfile->list);
 	strbuf_init(&tempfile->filename, 0);
+	tempfile->directorylen = 0;
 	return tempfile;
 }

@@ -198,6 +214,52 @@ struct tempfile *mks_tempfile_tsm(const char *filename_template, int suffixlen,
 	return tempfile;
 }

+struct tempfile *mks_tempfile_dt(const char *directory_template,
+				 const char *filename)
+{
+	struct tempfile *tempfile;
+	const char *tmpdir;
+	struct strbuf sb = STRBUF_INIT;
+	int fd;
+	size_t directorylen;
+
+	if (!ends_with(directory_template, "XXXXXX")) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	tmpdir = getenv("TMPDIR");
+	if (!tmpdir)
+		tmpdir = "/tmp";
+
+	strbuf_addf(&sb, "%s/%s", tmpdir, directory_template);
+	directorylen = sb.len;
+	if (!mkdtemp(sb.buf)) {
+		int orig_errno = errno;
+		strbuf_release(&sb);
+		errno = orig_errno;
+		return NULL;
+	}
+
+	strbuf_addf(&sb, "/%s", filename);
+	fd = open(sb.buf, O_CREAT | O_EXCL | O_RDWR, 0600);
+	if (fd < 0) {
+		int orig_errno = errno;
+		strbuf_setlen(&sb, directorylen);
+		rmdir(sb.buf);
+		strbuf_release(&sb);
+		errno = orig_errno;
+		return NULL;
+	}
+
+	tempfile = new_tempfile();
+	strbuf_swap(&tempfile->filename, &sb);
+	tempfile->directorylen = directorylen;
+	tempfile->fd = fd;
+	activate_tempfile(tempfile);
+	return tempfile;
+}
+
 struct tempfile *xmks_tempfile_m(const char *filename_template, int mode)
 {
 	struct tempfile *tempfile;
@@ -316,6 +378,7 @@ void delete_tempfile(struct tempfile **tempfile_p)

 	close_tempfile_gently(tempfile);
 	unlink_or_warn(tempfile->filename.buf);
+	remove_template_directory(tempfile, 0);
 	deactivate_tempfile(tempfile);
 	*tempfile_p = NULL;
 }
diff --git a/tempfile.h b/tempfile.h
index 4de3bc77d2..d7804a214a 100644
--- a/tempfile.h
+++ b/tempfile.h
@@ -82,6 +82,7 @@ struct tempfile {
 	FILE *volatile fp;
 	volatile pid_t owner;
 	struct strbuf filename;
+	size_t directorylen;
 };

 /*
@@ -198,6 +199,18 @@ static inline struct tempfile *xmks_tempfile(const char *filename_template)
 	return xmks_tempfile_m(filename_template, 0600);
 }

+/*
+ * Attempt to create a temporary directory in $TMPDIR and to create and
+ * open a file in that new directory. Derive the directory name from the
+ * template in the manner of mkdtemp(). Arrange for directory and file
+ * to be deleted if the program exits before they are deleted
+ * explicitly. On success return a tempfile whose "filename" member
+ * contains the full path of the file and its "fd" member is open for
+ * writing the file. On error return NULL and set errno appropriately.
+ */
+struct tempfile *mks_tempfile_dt(const char *directory_template,
+				 const char *filename);
+
 /*
  * Associate a stdio stream with the temporary file (which must still
  * be open). Return `NULL` (*without* deleting the file) on error. The
--
2.35.1

contrib/scalar/scalar.c, contrib/scalar/scalar.txt, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 00dcd4b50ef..30ce0799c7a 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -11,6 +11,7 @@
 #include "dir.h"
 #include "packfile.h"
 #include "help.h"
+#include "archive.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -261,6 +262,44 @@ static int unregister_dir(void)
 	return res;
 }
 
+static int add_directory_to_archiver(struct strvec *archiver_args,
+					  const char *path, int recurse)
+{
+	int at_root = !*path;
+	DIR *dir = opendir(at_root ? "." : path);
+	struct dirent *e;
+	struct strbuf buf = STRBUF_INIT;
+	size_t len;
+	int res = 0;
+
+	if (!dir)
+		return error(_("could not open directory '%s'"), path);
+
+	if (!at_root)
+		strbuf_addf(&buf, "%s/", path);
+	len = buf.len;
+	strvec_pushf(archiver_args, "--prefix=%s", buf.buf);
+
+	while (!res && (e = readdir(dir))) {
+		if (!strcmp(".", e->d_name) || !strcmp("..", e->d_name))
+			continue;
+
+		strbuf_setlen(&buf, len);
+		strbuf_addstr(&buf, e->d_name);
+
+		if (e->d_type == DT_REG)
+			strvec_pushf(archiver_args, "--add-file=%s", buf.buf);
+		else if (e->d_type != DT_DIR)
+			res = -1;
+		else if (recurse)
+		     add_directory_to_archiver(archiver_args, buf.buf, recurse);
+	}
+
+	closedir(dir);
+	strbuf_release(&buf);
+	return res;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -501,6 +540,109 @@ cleanup:
 	return res;
 }
 
+static int cmd_diagnose(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		N_("scalar diagnose [<enlistment>]"),
+		NULL
+	};
+	struct strbuf zip_path = STRBUF_INIT;
+	struct strvec archiver_args = STRVEC_INIT;
+	char **argv_copy = NULL;
+	int stdout_fd = -1, archiver_fd = -1;
+	time_t now = time(NULL);
+	struct tm tm;
+	struct strbuf path = STRBUF_INIT, buf = STRBUF_INIT;
+	size_t off;
+	int res = 0;
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	setup_enlistment_directory(argc, argv, usage, options, &zip_path);
+
+	strbuf_addstr(&zip_path, "/.scalarDiagnostics/scalar_");
+	strbuf_addftime(&zip_path,
+			"%Y%m%d_%H%M%S", localtime_r(&now, &tm), 0, 0);
+	strbuf_addstr(&zip_path, ".zip");
+	switch (safe_create_leading_directories(zip_path.buf)) {
+	case SCLD_EXISTS:
+	case SCLD_OK:
+		break;
+	default:
+		error_errno(_("could not create directory for '%s'"),
+			    zip_path.buf);
+		goto diagnose_cleanup;
+	}
+	stdout_fd = dup(1);
+	if (stdout_fd < 0) {
+		res = error_errno(_("could not duplicate stdout"));
+		goto diagnose_cleanup;
+	}
+
+	archiver_fd = xopen(zip_path.buf, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+	if (archiver_fd < 0 || dup2(archiver_fd, 1) < 0) {
+		res = error_errno(_("could not redirect output"));
+		goto diagnose_cleanup;
+	}
+
+	init_zip_archiver();
+	strvec_pushl(&archiver_args, "scalar-diagnose", "--format=zip", NULL);
+
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf,
+		      "--add-file-with-content=diagnostics.log:"
+		      "Collecting diagnostic info\n\n");
+	get_version_info(&buf, 1);
+
+	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	off = strchr(buf.buf, ':') + 1 - buf.buf;
+	write_or_die(stdout_fd, buf.buf + off, buf.len - off);
+	strvec_push(&archiver_args, buf.buf);
+
+	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/logs", 1)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/objects/info", 0)))
+		goto diagnose_cleanup;
+
+	strvec_pushl(&archiver_args, "--prefix=",
+		     oid_to_hex(the_hash_algo->empty_tree), "--", NULL);
+
+	/* `write_archive()` modifies the `argv` passed to it. Let it. */
+	argv_copy = xmemdupz(archiver_args.v,
+			     sizeof(char *) * archiver_args.nr);
+	res = write_archive(archiver_args.nr, (const char **)argv_copy, NULL,
+			    the_repository, NULL, 0);
+	if (res) {
+		error(_("failed to write archive"));
+		goto diagnose_cleanup;
+	}
+
+	if (!res)
+		printf("\n"
+		       "Diagnostics complete.\n"
+		       "All of the gathered info is captured in '%s'\n",
+		       zip_path.buf);
+
+diagnose_cleanup:
+	if (archiver_fd >= 0) {
+		close(1);
+		dup2(stdout_fd, 1);
+	}
+	free(argv_copy);
+	strvec_clear(&archiver_args);
+	strbuf_release(&zip_path);
+	strbuf_release(&path);
+	strbuf_release(&buf);
+
+	return res;
+}
+
 static int cmd_list(int argc, const char **argv)
 {
 	if (argc != 1)
@@ -802,6 +944,7 @@ static struct {
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
 	{ "version", cmd_version },
+	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
 };
 
diff --git a/contrib/scalar/scalar.txt b/contrib/scalar/scalar.txt
index f416d637289..22583fe046e 100644
--- a/contrib/scalar/scalar.txt
+++ b/contrib/scalar/scalar.txt
@@ -14,6 +14,7 @@ scalar register [<enlistment>]
 scalar unregister [<enlistment>]
 scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
 scalar reconfigure [ --all | <enlistment> ]
+scalar diagnose [<enlistment>]
 scalar delete <enlistment>
 
 DESCRIPTION
@@ -129,6 +130,17 @@ reconfigure the enlistment.
 With the `--all` option, all enlistments currently registered with Scalar
 will be reconfigured. Use this option after each Scalar upgrade.
 
+Diagnose
+~~~~~~~~
+
+diagnose [<enlistment>]::
+    When reporting issues with Scalar, it is often helpful to provide the
+    information gathered by this command, including logs and certain
+    statistics describing the data shape of the current enlistment.
++
+The output of this command is a `.zip` file that is written into
+a directory adjacent to the worktree in the `src` directory.
+
 Delete
 ~~~~~~
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 9d83fdf25e8..bbd07a44426 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -90,4 +90,18 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 	grep "cloned. does not exist" err
 '
 
+SQ="'"
+test_expect_success UNZIP 'scalar diagnose' '
+	scalar clone "file://$(pwd)" cloned --single-branch &&
+	scalar diagnose cloned >out &&
+	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
+	zip_path=$(cat zip_path) &&
+	test -n "$zip_path" &&
+	unzip -v "$zip_path" &&
+	folder=${zip_path%.zip} &&
+	test_path_is_missing "$folder" &&
+	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out
+'
+
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 30ce0799c7a..fd666376109 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -300,6 +300,58 @@ static int add_directory_to_archiver(struct strvec *archiver_args,
 	return res;
 }
 
+#ifndef WIN32
+#include <sys/statvfs.h>
+#endif
+
+static int get_disk_info(struct strbuf *out)
+{
+#ifdef WIN32
+	struct strbuf buf = STRBUF_INIT;
+	char volume_name[MAX_PATH], fs_name[MAX_PATH];
+	DWORD serial_number, component_length, flags;
+	ULARGE_INTEGER avail2caller, total, avail;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (!GetDiskFreeSpaceExA(buf.buf, &avail2caller, &total, &avail)) {
+		error(_("could not determine free disk size for '%s'"),
+		      buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_setlen(&buf, offset_1st_component(buf.buf));
+	if (!GetVolumeInformationA(buf.buf, volume_name, sizeof(volume_name),
+				   &serial_number, &component_length, &flags,
+				   fs_name, sizeof(fs_name))) {
+		error(_("could not get info for '%s'"), buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, avail2caller.QuadPart);
+	strbuf_addch(out, '\n');
+	strbuf_release(&buf);
+#else
+	struct strbuf buf = STRBUF_INIT;
+	struct statvfs stat;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (statvfs(buf.buf, &stat) < 0) {
+		error_errno(_("could not determine free disk size for '%s'"),
+			    buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, st_mult(stat.f_bsize, stat.f_bavail));
+	strbuf_addf(out, " (mount flags 0x%lx)\n", stat.f_flag);
+	strbuf_release(&buf);
+#endif
+	return 0;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -599,6 +651,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	get_version_info(&buf, 1);
 
 	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	get_disk_info(&buf);
 	off = strchr(buf.buf, ':') + 1 - buf.buf;
 	write_or_die(stdout_fd, buf.buf + off, buf.len - off);
 	strvec_push(&archiver_args, buf.buf);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index bbd07a44426..f3d037823c8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -94,6 +94,7 @@ SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	scalar diagnose cloned >out &&
+	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
 	zip_path=$(cat zip_path) &&
 	test -n "$zip_path" &&

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index fd666376109..331d48b2a80 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "help.h"
 #include "archive.h"
+#include "object-store.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -592,6 +593,29 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats_objects(const char *full_path, size_t full_path_len,
+				   const char *file_name, void *data)
+{
+	struct strbuf *buf = data;
+	struct stat st;
+
+	if (!stat(full_path, &st))
+		strbuf_addf(buf, "%-70s %16" PRIuMAX "\n", file_name,
+			    (uintmax_t)st.st_size);
+}
+
+static int dir_file_stats(struct object_directory *object_dir, void *data)
+{
+	struct strbuf *buf = data;
+
+	strbuf_addf(buf, "Contents of %s:\n", object_dir->path);
+
+	for_each_file_in_pack_dir(object_dir->path, dir_file_stats_objects,
+				  data);
+
+	return 0;
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -656,6 +680,12 @@ static int cmd_diagnose(int argc, const char **argv)
 	write_or_die(stdout_fd, buf.buf + off, buf.len - off);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=packs-local.txt:");
+	dir_file_stats(the_repository->objects->odb, &buf);
+	foreach_alt_odb(dir_file_stats, &buf);
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index f3d037823c8..e049221609d 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -93,6 +93,8 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
+	git repack &&
+	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
 	scalar diagnose cloned >out &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
@@ -102,7 +104,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
-	test_file_not_empty out
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
+	grep "$(pwd)/.git/objects" out
 '
 
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 331d48b2a80..537b97ae734 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -616,6 +616,60 @@ static int dir_file_stats(struct object_directory *object_dir, void *data)
 	return 0;
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -686,6 +740,11 @@ static int cmd_diagnose(int argc, const char **argv)
 	foreach_alt_odb(dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=objects-local.txt:");
+	loose_objs_stats(&buf, ".git/objects");
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index e049221609d..9b4eedbb0aa 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -95,6 +95,7 @@ test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	git repack &&
 	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
+	test_commit -C cloned/src loose &&
 	scalar diagnose cloned >out &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
@@ -106,7 +107,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
-	grep "$(pwd)/.git/objects" out
+	grep "$(pwd)/.git/objects" out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
+	grep "^Total: [1-9]" out
 '
 
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index a0edc9167b2..1789ce4c232 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -67,10 +67,15 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 +
-The `<path>` cannot contain any colon, the file mode is limited to
-a regular file, and the option may be subject to platform-dependent
-command-line limits. For non-trivial cases, write an untracked file
-and use `--add-file` instead.
+The `<path>` argument can start and end with a literal double-quote
+character. In this case, the backslash is interpreted as escape
+character. The path must be quoted if it contains a colon, to avoid
+the colon from being misinterpreted as the separator between the
+path and the contents.
++
+The file mode is limited to a regular file, and the option may be
+subject to platform-dependent command-line limits. For non-trivial
+cases, write an untracked file and use `--add-file` instead.
 
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
diff --git a/archive.c b/archive.c
index d798624cd5f..3b751027143 100644
--- a/archive.c
+++ b/archive.c
@@ -533,13 +533,37 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 			die(_("Not a regular file: %s"), path);
 		info->content = NULL; /* read the file later */
 	} else {
-		const char *colon = strchr(arg, ':');
 		char *p;
 
-		if (!colon)
-			die(_("missing colon: '%s'"), arg);
+		if (*arg != '"') {
+			const char *colon = strchr(arg, ':');
+
+			if (!colon)
+				die(_("missing colon: '%s'"), arg);
+			p = xstrndup(arg, colon - arg);
+			arg = colon + 1;
+		} else {
+			struct strbuf buf = STRBUF_INIT;
+			const char *orig = arg;
+
+			for (;;) {
+				if (!*(++arg))
+					die(_("unclosed quote: '%s'"), orig);
+				if (*arg == '"')
+					break;
+				if (*arg == '\\' && *(++arg) == '\0')
+					die(_("trailing backslash: '%s"), orig);
+				else
+					strbuf_addch(&buf, *arg);
+			}
+
+			if (*(++arg) != ':')
+				die(_("missing colon: '%s'"), orig);
+
+			p = strbuf_detach(&buf, NULL);
+			arg++;
+		}
 
-		p = xstrndup(arg, colon - arg);
 		if (!args->prefix)
 			path = p;
 		else {
@@ -548,7 +572,7 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 		}
 		memset(&info->stat, 0, sizeof(info->stat));
 		info->stat.st_mode = S_IFREG | 0644;
-		info->content = xstrdup(colon + 1);
+		info->content = xstrdup(arg);
 		info->stat.st_size = strlen(info->content);
 	}
 	item = string_list_append_nodup(&args->extra_files, path);
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 8ff1257f1a0..5b8bbfc2692 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -207,13 +207,21 @@ check_zip with_untracked
 check_added with_untracked untracked untracked
 
 test_expect_success UNZIP 'git archive --format=zip --add-file-with-content' '
+	if test_have_prereq FUNNYNAMES
+	then
+		QUOTED=quoted:colon
+	else
+		QUOTED=quoted
+	fi &&
 	git archive --format=zip >with_file_with_content.zip \
+		--add-file-with-content=\"$QUOTED\": \
 		--add-file-with-content=hello:world $EMPTY_TREE &&
 	test_when_finished "rm -rf tmp-unpack" &&
 	mkdir tmp-unpack && (
 		cd tmp-unpack &&
 		"$GIT_UNZIP" ../with_file_with_content.zip &&
 		test_path_is_file hello &&
+		test_path_is_file $QUOTED &&
 		test world = $(cat hello)
 	)
 '

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a7834..a0edc9167b2 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -61,6 +61,17 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 
+--add-file-with-content=<path>:<content>::
+	Add the specified contents to the archive.  Can be repeated to add
+	multiple files.  The path of the file in the archive is built
+	by concatenating the value for `--prefix` (if any) and the
+	basename of <file>.
++
+The `<path>` cannot contain any colon, the file mode is limited to
+a regular file, and the option may be subject to platform-dependent
+command-line limits. For non-trivial cases, write an untracked file
+and use `--add-file` instead.
+
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
 	as well (see <<ATTRIBUTES>>).
diff --git a/archive.c b/archive.c
index a3bbb091256..d798624cd5f 100644
--- a/archive.c
+++ b/archive.c
@@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 struct extra_file_info {
 	char *base;
 	struct stat stat;
+	void *content;
 };
 
 int write_archive_entries(struct archiver_args *args,
@@ -337,7 +338,13 @@ int write_archive_entries(struct archiver_args *args,
 		strbuf_addstr(&path_in_archive, basename(path));
 
 		strbuf_reset(&content);
-		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
+		if (info->content)
+			err = write_entry(args, &fake_oid, path_in_archive.buf,
+					  path_in_archive.len,
+					  info->stat.st_mode,
+					  info->content, info->stat.st_size);
+		else if (strbuf_read_file(&content, path,
+					  info->stat.st_size) < 0)
 			err = error_errno(_("could not read '%s'"), path);
 		else
 			err = write_entry(args, &fake_oid, path_in_archive.buf,
@@ -493,6 +500,7 @@ static void extra_file_info_clear(void *util, const char *str)
 {
 	struct extra_file_info *info = util;
 	free(info->base);
+	free(info->content);
 	free(info);
 }
 
@@ -514,14 +522,38 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	if (!arg)
 		return -1;
 
-	path = prefix_filename(args->prefix, arg);
-	item = string_list_append_nodup(&args->extra_files, path);
-	item->util = info = xmalloc(sizeof(*info));
+	info = xmalloc(sizeof(*info));
 	info->base = xstrdup_or_null(base);
-	if (stat(path, &info->stat))
-		die(_("File not found: %s"), path);
-	if (!S_ISREG(info->stat.st_mode))
-		die(_("Not a regular file: %s"), path);
+
+	if (!strcmp(opt->long_name, "add-file")) {
+		path = prefix_filename(args->prefix, arg);
+		if (stat(path, &info->stat))
+			die(_("File not found: %s"), path);
+		if (!S_ISREG(info->stat.st_mode))
+			die(_("Not a regular file: %s"), path);
+		info->content = NULL; /* read the file later */
+	} else {
+		const char *colon = strchr(arg, ':');
+		char *p;
+
+		if (!colon)
+			die(_("missing colon: '%s'"), arg);
+
+		p = xstrndup(arg, colon - arg);
+		if (!args->prefix)
+			path = p;
+		else {
+			path = prefix_filename(args->prefix, p);
+			free(p);
+		}
+		memset(&info->stat, 0, sizeof(info->stat));
+		info->stat.st_mode = S_IFREG | 0644;
+		info->content = xstrdup(colon + 1);
+		info->stat.st_size = strlen(info->content);
+	}
+	item = string_list_append_nodup(&args->extra_files, path);
+	item->util = info;
+
 	return 0;
 }
 
@@ -554,6 +586,9 @@ static int parse_archive_args(int argc, const char **argv,
 		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
 		  N_("add untracked file to archive"), 0, add_file_cb,
 		  (intptr_t)&base },
+		{ OPTION_CALLBACK, 0, "add-file-with-content", args,
+		  N_("path:content"), N_("add untracked file to archive"), 0,
+		  add_file_cb, (intptr_t)&base },
 		OPT_STRING('o', "output", &output, N_("file"),
 			N_("write the archive to this file")),
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 1e6d18b140e..8ff1257f1a0 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -206,6 +206,18 @@ test_expect_success 'git archive --format=zip --add-file' '
 check_zip with_untracked
 check_added with_untracked untracked untracked
 
+test_expect_success UNZIP 'git archive --format=zip --add-file-with-content' '
+	git archive --format=zip >with_file_with_content.zip \
+		--add-file-with-content=hello:world $EMPTY_TREE &&
+	test_when_finished "rm -rf tmp-unpack" &&
+	mkdir tmp-unpack && (
+		cd tmp-unpack &&
+		"$GIT_UNZIP" ../with_file_with_content.zip &&
+		test_path_is_file hello &&
+		test world = $(cat hello)
+	)
+'
+
 test_expect_success 'git archive --format=zip --add-file twice' '
 	echo untracked >untracked &&
 	git archive --format=zip --prefix=one/ --add-file=untracked \

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 1ce9c2b00e8..00dcd4b50ef 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -43,9 +43,11 @@ static void setup_enlistment_directory(int argc, const char **argv,
 		usage_with_options(usagestr, options);
 
 	/* find the worktree, determine its corresponding root */
-	if (argc == 1)
+	if (argc == 1) {
 		strbuf_add_absolute_path(&path, argv[0]);
-	else if (strbuf_getcwd(&path) < 0)
+		if (!is_directory(path.buf))
+			die(_("'%s' does not exist"), path.buf);
+	} else if (strbuf_getcwd(&path) < 0)
 		die(_("need a working directory"));
 
 	strbuf_trim_trailing_dir_sep(&path);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 2e1502ad45e..9d83fdf25e8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -85,4 +85,9 @@ test_expect_success 'scalar delete with enlistment' '
 	test_path_is_missing cloned
 '
 
+test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
+	! scalar run config cloned 2>err &&
+	grep "cloned. does not exist" err
+'
+
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index a290e52e1d2..df44902c909 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -300,6 +300,58 @@ static int add_directory_to_archiver(struct strvec *archiver_args,
 	return res;
 }
 
+#ifndef WIN32
+#include <sys/statvfs.h>
+#endif
+
+static int get_disk_info(struct strbuf *out)
+{
+#ifdef WIN32
+	struct strbuf buf = STRBUF_INIT;
+	char volume_name[MAX_PATH], fs_name[MAX_PATH];
+	DWORD serial_number, component_length, flags;
+	ULARGE_INTEGER avail2caller, total, avail;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (!GetDiskFreeSpaceExA(buf.buf, &avail2caller, &total, &avail)) {
+		error(_("could not determine free disk size for '%s'"),
+		      buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_setlen(&buf, offset_1st_component(buf.buf));
+	if (!GetVolumeInformationA(buf.buf, volume_name, sizeof(volume_name),
+				   &serial_number, &component_length, &flags,
+				   fs_name, sizeof(fs_name))) {
+		error(_("could not get info for '%s'"), buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, avail2caller.QuadPart);
+	strbuf_addch(out, '\n');
+	strbuf_release(&buf);
+#else
+	struct strbuf buf = STRBUF_INIT;
+	struct statvfs stat;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (statvfs(buf.buf, &stat) < 0) {
+		error_errno(_("could not determine free disk size for '%s'"),
+			    buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, st_mult(stat.f_bsize, stat.f_bavail));
+	strbuf_addf(out, " (mount flags 0x%lx)\n", stat.f_flag);
+	strbuf_release(&buf);
+#endif
+	return 0;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -596,6 +648,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	get_version_info(&buf, 1);
 
 	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	get_disk_info(&buf);
 	write_or_die(stdout_fd, buf.buf, buf.len);
 	strvec_pushf(&archiver_args,
 		     "--add-file-with-content=diagnostics.log:%.*s",
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index bbd07a44426..f3d037823c8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -94,6 +94,7 @@ SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	scalar diagnose cloned >out &&
+	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
 	zip_path=$(cat zip_path) &&
 	test -n "$zip_path" &&

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 9adde8cf4b9..f2fe3858eca 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -616,6 +616,60 @@ static int dir_file_stats(struct object_directory *object_dir, void *data)
 	return 0;
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -684,6 +738,11 @@ static int cmd_diagnose(int argc, const char **argv)
 	foreach_alt_odb(dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=objects-local.txt:");
+	loose_objs_stats(&buf, ".git/objects");
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index e049221609d..9b4eedbb0aa 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -95,6 +95,7 @@ test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	git repack &&
 	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
+	test_commit -C cloned/src loose &&
 	scalar diagnose cloned >out &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
@@ -106,7 +107,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
-	grep "$(pwd)/.git/objects" out
+	grep "$(pwd)/.git/objects" out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
+	grep "^Total: [1-9]" out
 '
 
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index df44902c909..9adde8cf4b9 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "help.h"
 #include "archive.h"
+#include "object-store.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -592,6 +593,29 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats_objects(const char *full_path, size_t full_path_len,
+				   const char *file_name, void *data)
+{
+	struct strbuf *buf = data;
+	struct stat st;
+
+	if (!stat(full_path, &st))
+		strbuf_addf(buf, "%-70s %16" PRIuMAX "\n", file_name,
+			    (uintmax_t)st.st_size);
+}
+
+static int dir_file_stats(struct object_directory *object_dir, void *data)
+{
+	struct strbuf *buf = data;
+
+	strbuf_addf(buf, "Contents of %s:\n", object_dir->path);
+
+	for_each_file_in_pack_dir(object_dir->path, dir_file_stats_objects,
+				  data);
+
+	return 0;
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -654,6 +678,12 @@ static int cmd_diagnose(int argc, const char **argv)
 		     "--add-file-with-content=diagnostics.log:%.*s",
 		     (int)buf.len, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=packs-local.txt:");
+	dir_file_stats(the_repository->objects->odb, &buf);
+	foreach_alt_odb(dir_file_stats, &buf);
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index f3d037823c8..e049221609d 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -93,6 +93,8 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
+	git repack &&
+	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
 	scalar diagnose cloned >out &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
@@ -102,7 +104,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
-	test_file_not_empty out
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
+	grep "$(pwd)/.git/objects" out
 '
 
 test_done

contrib/scalar/scalar.c, contrib/scalar/scalar.txt, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 00dcd4b50ef..a290e52e1d2 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -11,6 +11,7 @@
 #include "dir.h"
 #include "packfile.h"
 #include "help.h"
+#include "archive.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -261,6 +262,44 @@ static int unregister_dir(void)
 	return res;
 }
 
+static int add_directory_to_archiver(struct strvec *archiver_args,
+					  const char *path, int recurse)
+{
+	int at_root = !*path;
+	DIR *dir = opendir(at_root ? "." : path);
+	struct dirent *e;
+	struct strbuf buf = STRBUF_INIT;
+	size_t len;
+	int res = 0;
+
+	if (!dir)
+		return error(_("could not open directory '%s'"), path);
+
+	if (!at_root)
+		strbuf_addf(&buf, "%s/", path);
+	len = buf.len;
+	strvec_pushf(archiver_args, "--prefix=%s", buf.buf);
+
+	while (!res && (e = readdir(dir))) {
+		if (!strcmp(".", e->d_name) || !strcmp("..", e->d_name))
+			continue;
+
+		strbuf_setlen(&buf, len);
+		strbuf_addstr(&buf, e->d_name);
+
+		if (e->d_type == DT_REG)
+			strvec_pushf(archiver_args, "--add-file=%s", buf.buf);
+		else if (e->d_type != DT_DIR)
+			res = -1;
+		else if (recurse)
+		     add_directory_to_archiver(archiver_args, buf.buf, recurse);
+	}
+
+	closedir(dir);
+	strbuf_release(&buf);
+	return res;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -501,6 +540,107 @@ cleanup:
 	return res;
 }
 
+static int cmd_diagnose(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		N_("scalar diagnose [<enlistment>]"),
+		NULL
+	};
+	struct strbuf zip_path = STRBUF_INIT;
+	struct strvec archiver_args = STRVEC_INIT;
+	char **argv_copy = NULL;
+	int stdout_fd = -1, archiver_fd = -1;
+	time_t now = time(NULL);
+	struct tm tm;
+	struct strbuf path = STRBUF_INIT, buf = STRBUF_INIT;
+	int res = 0;
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	setup_enlistment_directory(argc, argv, usage, options, &zip_path);
+
+	strbuf_addstr(&zip_path, "/.scalarDiagnostics/scalar_");
+	strbuf_addftime(&zip_path,
+			"%Y%m%d_%H%M%S", localtime_r(&now, &tm), 0, 0);
+	strbuf_addstr(&zip_path, ".zip");
+	switch (safe_create_leading_directories(zip_path.buf)) {
+	case SCLD_EXISTS:
+	case SCLD_OK:
+		break;
+	default:
+		error_errno(_("could not create directory for '%s'"),
+			    zip_path.buf);
+		goto diagnose_cleanup;
+	}
+	stdout_fd = dup(1);
+	if (stdout_fd < 0) {
+		res = error_errno(_("could not duplicate stdout"));
+		goto diagnose_cleanup;
+	}
+
+	archiver_fd = xopen(zip_path.buf, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+	if (archiver_fd < 0 || dup2(archiver_fd, 1) < 0) {
+		res = error_errno(_("could not redirect output"));
+		goto diagnose_cleanup;
+	}
+
+	init_zip_archiver();
+	strvec_pushl(&archiver_args, "scalar-diagnose", "--format=zip", NULL);
+
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "Collecting diagnostic info\n\n");
+	get_version_info(&buf, 1);
+
+	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	write_or_die(stdout_fd, buf.buf, buf.len);
+	strvec_pushf(&archiver_args,
+		     "--add-file-with-content=diagnostics.log:%.*s",
+		     (int)buf.len, buf.buf);
+
+	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/logs", 1)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/objects/info", 0)))
+		goto diagnose_cleanup;
+
+	strvec_pushl(&archiver_args, "--prefix=",
+		     oid_to_hex(the_hash_algo->empty_tree), "--", NULL);
+
+	/* `write_archive()` modifies the `argv` passed to it. Let it. */
+	argv_copy = xmemdupz(archiver_args.v,
+			     sizeof(char *) * archiver_args.nr);
+	res = write_archive(archiver_args.nr, (const char **)argv_copy, NULL,
+			    the_repository, NULL, 0);
+	if (res) {
+		error(_("failed to write archive"));
+		goto diagnose_cleanup;
+	}
+
+	if (!res)
+		fprintf(stderr, "\n"
+		       "Diagnostics complete.\n"
+		       "All of the gathered info is captured in '%s'\n",
+		       zip_path.buf);
+
+diagnose_cleanup:
+	if (archiver_fd >= 0) {
+		close(1);
+		dup2(stdout_fd, 1);
+	}
+	free(argv_copy);
+	strvec_clear(&archiver_args);
+	strbuf_release(&zip_path);
+	strbuf_release(&path);
+	strbuf_release(&buf);
+
+	return res;
+}
+
 static int cmd_list(int argc, const char **argv)
 {
 	if (argc != 1)
@@ -802,6 +942,7 @@ static struct {
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
 	{ "version", cmd_version },
+	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
 };
 
diff --git a/contrib/scalar/scalar.txt b/contrib/scalar/scalar.txt
index f416d637289..22583fe046e 100644
--- a/contrib/scalar/scalar.txt
+++ b/contrib/scalar/scalar.txt
@@ -14,6 +14,7 @@ scalar register [<enlistment>]
 scalar unregister [<enlistment>]
 scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
 scalar reconfigure [ --all | <enlistment> ]
+scalar diagnose [<enlistment>]
 scalar delete <enlistment>
 
 DESCRIPTION
@@ -129,6 +130,17 @@ reconfigure the enlistment.
 With the `--all` option, all enlistments currently registered with Scalar
 will be reconfigured. Use this option after each Scalar upgrade.
 
+Diagnose
+~~~~~~~~
+
+diagnose [<enlistment>]::
+    When reporting issues with Scalar, it is often helpful to provide the
+    information gathered by this command, including logs and certain
+    statistics describing the data shape of the current enlistment.
++
+The output of this command is a `.zip` file that is written into
+a directory adjacent to the worktree in the `src` directory.
+
 Delete
 ~~~~~~
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 9d83fdf25e8..bbd07a44426 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -90,4 +90,18 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 	grep "cloned. does not exist" err
 '
 
+SQ="'"
+test_expect_success UNZIP 'scalar diagnose' '
+	scalar clone "file://$(pwd)" cloned --single-branch &&
+	scalar diagnose cloned >out &&
+	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
+	zip_path=$(cat zip_path) &&
+	test -n "$zip_path" &&
+	unzip -v "$zip_path" &&
+	folder=${zip_path%.zip} &&
+	test_path_is_missing "$folder" &&
+	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out
+'
+
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index a0edc9167b2..21eab5690ad 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -67,10 +67,16 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 +
-The `<path>` cannot contain any colon, the file mode is limited to
-a regular file, and the option may be subject to platform-dependent
-command-line limits. For non-trivial cases, write an untracked file
-and use `--add-file` instead.
+The `<path>` argument can start and end with a literal double-quote
+character; The contained file name is interpreted as a C-style string,
+i.e. the backslash is interpreted as escape character. The path must
+be quoted if it contains a colon, to avoid the colon from being
+misinterpreted as the separator between the path and the contents, or
+if the path begins or ends with a double-quote character.
++
+The file mode is limited to a regular file, and the option may be
+subject to platform-dependent command-line limits. For non-trivial
+cases, write an untracked file and use `--add-file` instead.
 
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
diff --git a/archive.c b/archive.c
index d798624cd5f..477eba60ac3 100644
--- a/archive.c
+++ b/archive.c
@@ -9,6 +9,7 @@
 #include "parse-options.h"
 #include "unpack-trees.h"
 #include "dir.h"
+#include "quote.h"
 
 static char const * const archive_usage[] = {
 	N_("git archive [<options>] <tree-ish> [<path>...]"),
@@ -533,22 +534,31 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 			die(_("Not a regular file: %s"), path);
 		info->content = NULL; /* read the file later */
 	} else {
-		const char *colon = strchr(arg, ':');
-		char *p;
+		struct strbuf buf = STRBUF_INIT;
+		const char *p = arg;
+
+		if (*p != '"')
+			p = strchr(p, ':');
+		else if (unquote_c_style(&buf, p, &p) < 0)
+			die(_("unclosed quote: '%s'"), arg);
 
-		if (!colon)
+		if (!p || *p != ':')
 			die(_("missing colon: '%s'"), arg);
 
-		p = xstrndup(arg, colon - arg);
-		if (!args->prefix)
-			path = p;
-		else {
-			path = prefix_filename(args->prefix, p);
-			free(p);
+		if (p == arg)
+			die(_("empty file name: '%s'"), arg);
+
+		path = buf.len ?
+			strbuf_detach(&buf, NULL) : xstrndup(arg, p - arg);
+
+		if (args->prefix) {
+			char *save = path;
+			path = prefix_filename(args->prefix, path);
+			free(save);
 		}
 		memset(&info->stat, 0, sizeof(info->stat));
 		info->stat.st_mode = S_IFREG | 0644;
-		info->content = xstrdup(colon + 1);
+		info->content = xstrdup(p + 1);
 		info->stat.st_size = strlen(info->content);
 	}
 	item = string_list_append_nodup(&args->extra_files, path);
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 8ff1257f1a0..5b8bbfc2692 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -207,13 +207,21 @@ check_zip with_untracked
 check_added with_untracked untracked untracked
 
 test_expect_success UNZIP 'git archive --format=zip --add-file-with-content' '
+	if test_have_prereq FUNNYNAMES
+	then
+		QUOTED=quoted:colon
+	else
+		QUOTED=quoted
+	fi &&
 	git archive --format=zip >with_file_with_content.zip \
+		--add-file-with-content=\"$QUOTED\": \
 		--add-file-with-content=hello:world $EMPTY_TREE &&
 	test_when_finished "rm -rf tmp-unpack" &&
 	mkdir tmp-unpack && (
 		cd tmp-unpack &&
 		"$GIT_UNZIP" ../with_file_with_content.zip &&
 		test_path_is_file hello &&
+		test_path_is_file $QUOTED &&
 		test world = $(cat hello)
 	)
 '

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 1ce9c2b00e8..00dcd4b50ef 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -43,9 +43,11 @@ static void setup_enlistment_directory(int argc, const char **argv,
 		usage_with_options(usagestr, options);
 
 	/* find the worktree, determine its corresponding root */
-	if (argc == 1)
+	if (argc == 1) {
 		strbuf_add_absolute_path(&path, argv[0]);
-	else if (strbuf_getcwd(&path) < 0)
+		if (!is_directory(path.buf))
+			die(_("'%s' does not exist"), path.buf);
+	} else if (strbuf_getcwd(&path) < 0)
 		die(_("need a working directory"));
 
 	strbuf_trim_trailing_dir_sep(&path);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 2e1502ad45e..9d83fdf25e8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -85,4 +85,9 @@ test_expect_success 'scalar delete with enlistment' '
 	test_path_is_missing cloned
 '
 
+test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
+	! scalar run config cloned 2>err &&
+	grep "cloned. does not exist" err
+'
+
 test_done

diff --git i/t/test-lib-functions.sh w/t/test-lib-functions.sh
index 93c03380d4..8899eaabed 100644
--- i/t/test-lib-functions.sh
+++ w/t/test-lib-functions.sh
@@ -1106,7 +1106,7 @@ test_must_fail_acceptable () {
 	fi
 
 	case "$1" in
-	git|__git*|test-tool|test_terminal)
+	git|__git*|scalar|test-tool|test_terminal)
 		return 0
 		;;
 	*)

contrib/scalar/scalar.c, contrib/scalar/scalar.txt, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 00dcd4b50ef..367a2c50e25 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -11,6 +11,7 @@
 #include "dir.h"
 #include "packfile.h"
 #include "help.h"
+#include "archive.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -261,6 +262,47 @@ static int unregister_dir(void)
 	return res;
 }
 
+static int add_directory_to_archiver(struct strvec *archiver_args,
+					  const char *path, int recurse)
+{
+	int at_root = !*path;
+	DIR *dir = opendir(at_root ? "." : path);
+	struct dirent *e;
+	struct strbuf buf = STRBUF_INIT;
+	size_t len;
+	int res = 0;
+
+	if (!dir)
+		return error(_("could not open directory '%s'"), path);
+
+	if (!at_root)
+		strbuf_addf(&buf, "%s/", path);
+	len = buf.len;
+	strvec_pushf(archiver_args, "--prefix=%s", buf.buf);
+
+	while (!res && (e = readdir(dir))) {
+		if (!strcmp(".", e->d_name) || !strcmp("..", e->d_name))
+			continue;
+
+		strbuf_setlen(&buf, len);
+		strbuf_addstr(&buf, e->d_name);
+
+		if (e->d_type == DT_REG)
+			strvec_pushf(archiver_args, "--add-file=%s", buf.buf);
+		else if (e->d_type != DT_DIR)
+			warning(_("skipping '%s', which is neither file nor "
+				  "directory"), buf.buf);
+		else if (recurse &&
+			 add_directory_to_archiver(archiver_args,
+						   buf.buf, recurse) < 0)
+			res = -1;
+	}
+
+	closedir(dir);
+	strbuf_release(&buf);
+	return res;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -501,6 +543,107 @@ cleanup:
 	return res;
 }
 
+static int cmd_diagnose(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		N_("scalar diagnose [<enlistment>]"),
+		NULL
+	};
+	struct strbuf zip_path = STRBUF_INIT;
+	struct strvec archiver_args = STRVEC_INIT;
+	char **argv_copy = NULL;
+	int stdout_fd = -1, archiver_fd = -1;
+	time_t now = time(NULL);
+	struct tm tm;
+	struct strbuf path = STRBUF_INIT, buf = STRBUF_INIT;
+	int res = 0;
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	setup_enlistment_directory(argc, argv, usage, options, &zip_path);
+
+	strbuf_addstr(&zip_path, "/.scalarDiagnostics/scalar_");
+	strbuf_addftime(&zip_path,
+			"%Y%m%d_%H%M%S", localtime_r(&now, &tm), 0, 0);
+	strbuf_addstr(&zip_path, ".zip");
+	switch (safe_create_leading_directories(zip_path.buf)) {
+	case SCLD_EXISTS:
+	case SCLD_OK:
+		break;
+	default:
+		error_errno(_("could not create directory for '%s'"),
+			    zip_path.buf);
+		goto diagnose_cleanup;
+	}
+	stdout_fd = dup(1);
+	if (stdout_fd < 0) {
+		res = error_errno(_("could not duplicate stdout"));
+		goto diagnose_cleanup;
+	}
+
+	archiver_fd = xopen(zip_path.buf, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+	if (archiver_fd < 0 || dup2(archiver_fd, 1) < 0) {
+		res = error_errno(_("could not redirect output"));
+		goto diagnose_cleanup;
+	}
+
+	init_zip_archiver();
+	strvec_pushl(&archiver_args, "scalar-diagnose", "--format=zip", NULL);
+
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "Collecting diagnostic info\n\n");
+	get_version_info(&buf, 1);
+
+	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	write_or_die(stdout_fd, buf.buf, buf.len);
+	strvec_pushf(&archiver_args,
+		     "--add-file-with-content=diagnostics.log:%.*s",
+		     (int)buf.len, buf.buf);
+
+	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/logs", 1)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/objects/info", 0)))
+		goto diagnose_cleanup;
+
+	strvec_pushl(&archiver_args, "--prefix=",
+		     oid_to_hex(the_hash_algo->empty_tree), "--", NULL);
+
+	/* `write_archive()` modifies the `argv` passed to it. Let it. */
+	argv_copy = xmemdupz(archiver_args.v,
+			     sizeof(char *) * archiver_args.nr);
+	res = write_archive(archiver_args.nr, (const char **)argv_copy, NULL,
+			    the_repository, NULL, 0);
+	if (res) {
+		error(_("failed to write archive"));
+		goto diagnose_cleanup;
+	}
+
+	if (!res)
+		fprintf(stderr, "\n"
+		       "Diagnostics complete.\n"
+		       "All of the gathered info is captured in '%s'\n",
+		       zip_path.buf);
+
+diagnose_cleanup:
+	if (archiver_fd >= 0) {
+		close(1);
+		dup2(stdout_fd, 1);
+	}
+	free(argv_copy);
+	strvec_clear(&archiver_args);
+	strbuf_release(&zip_path);
+	strbuf_release(&path);
+	strbuf_release(&buf);
+
+	return res;
+}
+
 static int cmd_list(int argc, const char **argv)
 {
 	if (argc != 1)
@@ -802,6 +945,7 @@ static struct {
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
 	{ "version", cmd_version },
+	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
 };
 
diff --git a/contrib/scalar/scalar.txt b/contrib/scalar/scalar.txt
index f416d637289..22583fe046e 100644
--- a/contrib/scalar/scalar.txt
+++ b/contrib/scalar/scalar.txt
@@ -14,6 +14,7 @@ scalar register [<enlistment>]
 scalar unregister [<enlistment>]
 scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
 scalar reconfigure [ --all | <enlistment> ]
+scalar diagnose [<enlistment>]
 scalar delete <enlistment>
 
 DESCRIPTION
@@ -129,6 +130,17 @@ reconfigure the enlistment.
 With the `--all` option, all enlistments currently registered with Scalar
 will be reconfigured. Use this option after each Scalar upgrade.
 
+Diagnose
+~~~~~~~~
+
+diagnose [<enlistment>]::
+    When reporting issues with Scalar, it is often helpful to provide the
+    information gathered by this command, including logs and certain
+    statistics describing the data shape of the current enlistment.
++
+The output of this command is a `.zip` file that is written into
+a directory adjacent to the worktree in the `src` directory.
+
 Delete
 ~~~~~~
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 9d83fdf25e8..6802d317258 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -90,4 +90,18 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 	grep "cloned. does not exist" err
 '
 
+SQ="'"
+test_expect_success UNZIP 'scalar diagnose' '
+	scalar clone "file://$(pwd)" cloned --single-branch &&
+	scalar diagnose cloned >out 2>err &&
+	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
+	zip_path=$(cat zip_path) &&
+	test -n "$zip_path" &&
+	unzip -v "$zip_path" &&
+	folder=${zip_path%.zip} &&
+	test_path_is_missing "$folder" &&
+	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out
+'
+
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 34cbec59b45..e8e0a5ec473 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "help.h"
 #include "archive.h"
+#include "object-store.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -595,6 +596,29 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats_objects(const char *full_path, size_t full_path_len,
+				   const char *file_name, void *data)
+{
+	struct strbuf *buf = data;
+	struct stat st;
+
+	if (!stat(full_path, &st))
+		strbuf_addf(buf, "%-70s %16" PRIuMAX "\n", file_name,
+			    (uintmax_t)st.st_size);
+}
+
+static int dir_file_stats(struct object_directory *object_dir, void *data)
+{
+	struct strbuf *buf = data;
+
+	strbuf_addf(buf, "Contents of %s:\n", object_dir->path);
+
+	for_each_file_in_pack_dir(object_dir->path, dir_file_stats_objects,
+				  data);
+
+	return 0;
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -657,6 +681,12 @@ static int cmd_diagnose(int argc, const char **argv)
 		     "--add-file-with-content=diagnostics.log:%.*s",
 		     (int)buf.len, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=packs-local.txt:");
+	dir_file_stats(the_repository->objects->odb, &buf);
+	foreach_alt_odb(dir_file_stats, &buf);
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 934b2485d91..3dd5650cceb 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -93,6 +93,8 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
+	git repack &&
+	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -102,7 +104,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
-	test_file_not_empty out
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
+	grep "$(pwd)/.git/objects" out
 '
 
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 367a2c50e25..34cbec59b45 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -303,6 +303,58 @@ static int add_directory_to_archiver(struct strvec *archiver_args,
 	return res;
 }
 
+#ifndef WIN32
+#include <sys/statvfs.h>
+#endif
+
+static int get_disk_info(struct strbuf *out)
+{
+#ifdef WIN32
+	struct strbuf buf = STRBUF_INIT;
+	char volume_name[MAX_PATH], fs_name[MAX_PATH];
+	DWORD serial_number, component_length, flags;
+	ULARGE_INTEGER avail2caller, total, avail;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (!GetDiskFreeSpaceExA(buf.buf, &avail2caller, &total, &avail)) {
+		error(_("could not determine free disk size for '%s'"),
+		      buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_setlen(&buf, offset_1st_component(buf.buf));
+	if (!GetVolumeInformationA(buf.buf, volume_name, sizeof(volume_name),
+				   &serial_number, &component_length, &flags,
+				   fs_name, sizeof(fs_name))) {
+		error(_("could not get info for '%s'"), buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, avail2caller.QuadPart);
+	strbuf_addch(out, '\n');
+	strbuf_release(&buf);
+#else
+	struct strbuf buf = STRBUF_INIT;
+	struct statvfs stat;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (statvfs(buf.buf, &stat) < 0) {
+		error_errno(_("could not determine free disk size for '%s'"),
+			    buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, st_mult(stat.f_bsize, stat.f_bavail));
+	strbuf_addf(out, " (mount flags 0x%lx)\n", stat.f_flag);
+	strbuf_release(&buf);
+#endif
+	return 0;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -599,6 +651,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	get_version_info(&buf, 1);
 
 	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	get_disk_info(&buf);
 	write_or_die(stdout_fd, buf.buf, buf.len);
 	strvec_pushf(&archiver_args,
 		     "--add-file-with-content=diagnostics.log:%.*s",
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 6802d317258..934b2485d91 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -94,6 +94,7 @@ SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	scalar diagnose cloned >out 2>err &&
+	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
 	zip_path=$(cat zip_path) &&
 	test -n "$zip_path" &&

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a7834..a0edc9167b2 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -61,6 +61,17 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 
+--add-file-with-content=<path>:<content>::
+	Add the specified contents to the archive.  Can be repeated to add
+	multiple files.  The path of the file in the archive is built
+	by concatenating the value for `--prefix` (if any) and the
+	basename of <file>.
++
+The `<path>` cannot contain any colon, the file mode is limited to
+a regular file, and the option may be subject to platform-dependent
+command-line limits. For non-trivial cases, write an untracked file
+and use `--add-file` instead.
+
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
 	as well (see <<ATTRIBUTES>>).
diff --git a/archive.c b/archive.c
index a3bbb091256..d798624cd5f 100644
--- a/archive.c
+++ b/archive.c
@@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 struct extra_file_info {
 	char *base;
 	struct stat stat;
+	void *content;
 };
 
 int write_archive_entries(struct archiver_args *args,
@@ -337,7 +338,13 @@ int write_archive_entries(struct archiver_args *args,
 		strbuf_addstr(&path_in_archive, basename(path));
 
 		strbuf_reset(&content);
-		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
+		if (info->content)
+			err = write_entry(args, &fake_oid, path_in_archive.buf,
+					  path_in_archive.len,
+					  info->stat.st_mode,
+					  info->content, info->stat.st_size);
+		else if (strbuf_read_file(&content, path,
+					  info->stat.st_size) < 0)
 			err = error_errno(_("could not read '%s'"), path);
 		else
 			err = write_entry(args, &fake_oid, path_in_archive.buf,
@@ -493,6 +500,7 @@ static void extra_file_info_clear(void *util, const char *str)
 {
 	struct extra_file_info *info = util;
 	free(info->base);
+	free(info->content);
 	free(info);
 }
 
@@ -514,14 +522,38 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	if (!arg)
 		return -1;
 
-	path = prefix_filename(args->prefix, arg);
-	item = string_list_append_nodup(&args->extra_files, path);
-	item->util = info = xmalloc(sizeof(*info));
+	info = xmalloc(sizeof(*info));
 	info->base = xstrdup_or_null(base);
-	if (stat(path, &info->stat))
-		die(_("File not found: %s"), path);
-	if (!S_ISREG(info->stat.st_mode))
-		die(_("Not a regular file: %s"), path);
+
+	if (!strcmp(opt->long_name, "add-file")) {
+		path = prefix_filename(args->prefix, arg);
+		if (stat(path, &info->stat))
+			die(_("File not found: %s"), path);
+		if (!S_ISREG(info->stat.st_mode))
+			die(_("Not a regular file: %s"), path);
+		info->content = NULL; /* read the file later */
+	} else {
+		const char *colon = strchr(arg, ':');
+		char *p;
+
+		if (!colon)
+			die(_("missing colon: '%s'"), arg);
+
+		p = xstrndup(arg, colon - arg);
+		if (!args->prefix)
+			path = p;
+		else {
+			path = prefix_filename(args->prefix, p);
+			free(p);
+		}
+		memset(&info->stat, 0, sizeof(info->stat));
+		info->stat.st_mode = S_IFREG | 0644;
+		info->content = xstrdup(colon + 1);
+		info->stat.st_size = strlen(info->content);
+	}
+	item = string_list_append_nodup(&args->extra_files, path);
+	item->util = info;
+
 	return 0;
 }
 
@@ -554,6 +586,9 @@ static int parse_archive_args(int argc, const char **argv,
 		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
 		  N_("add untracked file to archive"), 0, add_file_cb,
 		  (intptr_t)&base },
+		{ OPTION_CALLBACK, 0, "add-file-with-content", args,
+		  N_("path:content"), N_("add untracked file to archive"), 0,
+		  add_file_cb, (intptr_t)&base },
 		OPT_STRING('o', "output", &output, N_("file"),
 			N_("write the archive to this file")),
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 1e6d18b140e..8ff1257f1a0 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -206,6 +206,18 @@ test_expect_success 'git archive --format=zip --add-file' '
 check_zip with_untracked
 check_added with_untracked untracked untracked
 
+test_expect_success UNZIP 'git archive --format=zip --add-file-with-content' '
+	git archive --format=zip >with_file_with_content.zip \
+		--add-file-with-content=hello:world $EMPTY_TREE &&
+	test_when_finished "rm -rf tmp-unpack" &&
+	mkdir tmp-unpack && (
+		cd tmp-unpack &&
+		"$GIT_UNZIP" ../with_file_with_content.zip &&
+		test_path_is_file hello &&
+		test world = $(cat hello)
+	)
+'
+
 test_expect_success 'git archive --format=zip --add-file twice' '
 	echo untracked >untracked &&
 	git archive --format=zip --prefix=one/ --add-file=untracked \

diff --git a/archive.c b/archive.c
index e29d0e00f6..12a08af531 100644
--- a/archive.c
+++ b/archive.c
@@ -342,7 +342,7 @@ int write_archive_entries(struct archiver_args *args,
 		else
 			err = write_entry(args, &fake_oid, path_in_archive.buf,
 					  path_in_archive.len,
-					  info->stat.st_mode,
+					  canon_mode(info->stat.st_mode),
 					  content.buf, content.len);
 		if (err)
 			break;

diff --git a/archive.c b/archive.c
index 477eba60ac..98c7449ea1 100644
--- a/archive.c
+++ b/archive.c
@@ -533,7 +533,7 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 		if (!S_ISREG(info->stat.st_mode))
 			die(_("Not a regular file: %s"), path);
 		info->content = NULL; /* read the file later */
-	} else {
+	} else if (!strcmp(opt->long_name, "add-file-with-content")) {
 		struct strbuf buf = STRBUF_INIT;
 		const char *p = arg;
 
@@ -560,6 +560,8 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 		info->stat.st_mode = S_IFREG | 0644;
 		info->content = xstrdup(p + 1);
 		info->stat.st_size = strlen(info->content);
+	} else {
+		BUG("add_file_cb() called for %s", opt->long_name);
 	}
 	item = string_list_append_nodup(&args->extra_files, path);
 	item->util = info;

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index e8e0a5ec473..03da7452d83 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -619,6 +619,60 @@ static int dir_file_stats(struct object_directory *object_dir, void *data)
 	return 0;
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -687,6 +741,11 @@ static int cmd_diagnose(int argc, const char **argv)
 	foreach_alt_odb(dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=objects-local.txt:");
+	loose_objs_stats(&buf, ".git/objects");
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 3dd5650cceb..72023a1ca1d 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -95,6 +95,7 @@ test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	git repack &&
 	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
+	test_commit -C cloned/src loose &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -106,7 +107,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
-	grep "$(pwd)/.git/objects" out
+	grep "$(pwd)/.git/objects" out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
+	grep "^Total: [1-9]" out
 '
 
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a7834..893cb1075bf 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -61,6 +61,17 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 
+--add-virtual-file=<path>:<content>::
+	Add the specified contents to the archive.  Can be repeated to add
+	multiple files.  The path of the file in the archive is built
+	by concatenating the value for `--prefix` (if any) and the
+	basename of <file>.
++
+The `<path>` cannot contain any colon, the file mode is limited to
+a regular file, and the option may be subject to platform-dependent
+command-line limits. For non-trivial cases, write an untracked file
+and use `--add-file` instead.
+
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
 	as well (see <<ATTRIBUTES>>).
diff --git a/archive.c b/archive.c
index a3bbb091256..d20e16fa819 100644
--- a/archive.c
+++ b/archive.c
@@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 struct extra_file_info {
 	char *base;
 	struct stat stat;
+	void *content;
 };
 
 int write_archive_entries(struct archiver_args *args,
@@ -337,7 +338,13 @@ int write_archive_entries(struct archiver_args *args,
 		strbuf_addstr(&path_in_archive, basename(path));
 
 		strbuf_reset(&content);
-		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
+		if (info->content)
+			err = write_entry(args, &fake_oid, path_in_archive.buf,
+					  path_in_archive.len,
+					  info->stat.st_mode,
+					  info->content, info->stat.st_size);
+		else if (strbuf_read_file(&content, path,
+					  info->stat.st_size) < 0)
 			err = error_errno(_("could not read '%s'"), path);
 		else
 			err = write_entry(args, &fake_oid, path_in_archive.buf,
@@ -493,6 +500,7 @@ static void extra_file_info_clear(void *util, const char *str)
 {
 	struct extra_file_info *info = util;
 	free(info->base);
+	free(info->content);
 	free(info);
 }
 
@@ -514,14 +522,40 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	if (!arg)
 		return -1;
 
-	path = prefix_filename(args->prefix, arg);
-	item = string_list_append_nodup(&args->extra_files, path);
-	item->util = info = xmalloc(sizeof(*info));
+	info = xmalloc(sizeof(*info));
 	info->base = xstrdup_or_null(base);
-	if (stat(path, &info->stat))
-		die(_("File not found: %s"), path);
-	if (!S_ISREG(info->stat.st_mode))
-		die(_("Not a regular file: %s"), path);
+
+	if (!strcmp(opt->long_name, "add-file")) {
+		path = prefix_filename(args->prefix, arg);
+		if (stat(path, &info->stat))
+			die(_("File not found: %s"), path);
+		if (!S_ISREG(info->stat.st_mode))
+			die(_("Not a regular file: %s"), path);
+		info->content = NULL; /* read the file later */
+	} else if (!strcmp(opt->long_name, "add-virtual-file")) {
+		const char *colon = strchr(arg, ':');
+		char *p;
+
+		if (!colon)
+			die(_("missing colon: '%s'"), arg);
+
+		p = xstrndup(arg, colon - arg);
+		if (!args->prefix)
+			path = p;
+		else {
+			path = prefix_filename(args->prefix, p);
+			free(p);
+		}
+		memset(&info->stat, 0, sizeof(info->stat));
+		info->stat.st_mode = S_IFREG | 0644;
+		info->content = xstrdup(colon + 1);
+		info->stat.st_size = strlen(info->content);
+	} else {
+		BUG("add_file_cb() called for %s", opt->long_name);
+	}
+	item = string_list_append_nodup(&args->extra_files, path);
+	item->util = info;
+
 	return 0;
 }
 
@@ -554,6 +588,9 @@ static int parse_archive_args(int argc, const char **argv,
 		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
 		  N_("add untracked file to archive"), 0, add_file_cb,
 		  (intptr_t)&base },
+		{ OPTION_CALLBACK, 0, "add-virtual-file", args,
+		  N_("path:content"), N_("add untracked file to archive"), 0,
+		  add_file_cb, (intptr_t)&base },
 		OPT_STRING('o', "output", &output, N_("file"),
 			N_("write the archive to this file")),
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 1e6d18b140e..ebc26e89a9b 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -206,6 +206,18 @@ test_expect_success 'git archive --format=zip --add-file' '
 check_zip with_untracked
 check_added with_untracked untracked untracked
 
+test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
+	git archive --format=zip >with_file_with_content.zip \
+		--add-virtual-file=hello:world $EMPTY_TREE &&
+	test_when_finished "rm -rf tmp-unpack" &&
+	mkdir tmp-unpack && (
+		cd tmp-unpack &&
+		"$GIT_UNZIP" ../with_file_with_content.zip &&
+		test_path_is_file hello &&
+		test world = $(cat hello)
+	)
+'
+
 test_expect_success 'git archive --format=zip --add-file twice' '
 	echo untracked >untracked &&
 	git archive --format=zip --prefix=one/ --add-file=untracked \

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index 893cb1075bf..54de945a84e 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -67,10 +67,16 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 +
-The `<path>` cannot contain any colon, the file mode is limited to
-a regular file, and the option may be subject to platform-dependent
-command-line limits. For non-trivial cases, write an untracked file
-and use `--add-file` instead.
+The `<path>` argument can start and end with a literal double-quote
+character; The contained file name is interpreted as a C-style string,
+i.e. the backslash is interpreted as escape character. The path must
+be quoted if it contains a colon, to avoid the colon from being
+misinterpreted as the separator between the path and the contents, or
+if the path begins or ends with a double-quote character.
++
+The file mode is limited to a regular file, and the option may be
+subject to platform-dependent command-line limits. For non-trivial
+cases, write an untracked file and use `--add-file` instead.
 
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
diff --git a/archive.c b/archive.c
index d20e16fa819..b7756b91200 100644
--- a/archive.c
+++ b/archive.c
@@ -9,6 +9,7 @@
 #include "parse-options.h"
 #include "unpack-trees.h"
 #include "dir.h"
+#include "quote.h"
 
 static char const * const archive_usage[] = {
 	N_("git archive [<options>] <tree-ish> [<path>...]"),
@@ -533,22 +534,31 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 			die(_("Not a regular file: %s"), path);
 		info->content = NULL; /* read the file later */
 	} else if (!strcmp(opt->long_name, "add-virtual-file")) {
-		const char *colon = strchr(arg, ':');
-		char *p;
+		struct strbuf buf = STRBUF_INIT;
+		const char *p = arg;
+
+		if (*p != '"')
+			p = strchr(p, ':');
+		else if (unquote_c_style(&buf, p, &p) < 0)
+			die(_("unclosed quote: '%s'"), arg);
 
-		if (!colon)
+		if (!p || *p != ':')
 			die(_("missing colon: '%s'"), arg);
 
-		p = xstrndup(arg, colon - arg);
-		if (!args->prefix)
-			path = p;
-		else {
-			path = prefix_filename(args->prefix, p);
-			free(p);
+		if (p == arg)
+			die(_("empty file name: '%s'"), arg);
+
+		path = buf.len ?
+			strbuf_detach(&buf, NULL) : xstrndup(arg, p - arg);
+
+		if (args->prefix) {
+			char *save = path;
+			path = prefix_filename(args->prefix, path);
+			free(save);
 		}
 		memset(&info->stat, 0, sizeof(info->stat));
 		info->stat.st_mode = S_IFREG | 0644;
-		info->content = xstrdup(colon + 1);
+		info->content = xstrdup(p + 1);
 		info->stat.st_size = strlen(info->content);
 	} else {
 		BUG("add_file_cb() called for %s", opt->long_name);
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index ebc26e89a9b..50932a866c9 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -207,13 +207,21 @@ check_zip with_untracked
 check_added with_untracked untracked untracked
 
 test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
+	if test_have_prereq FUNNYNAMES
+	then
+		QUOTED=quoted:colon
+	else
+		QUOTED=quoted
+	fi &&
 	git archive --format=zip >with_file_with_content.zip \
+		--add-virtual-file=\"$QUOTED\": \
 		--add-virtual-file=hello:world $EMPTY_TREE &&
 	test_when_finished "rm -rf tmp-unpack" &&
 	mkdir tmp-unpack && (
 		cd tmp-unpack &&
 		"$GIT_UNZIP" ../with_file_with_content.zip &&
 		test_path_is_file hello &&
+		test_path_is_file $QUOTED &&
 		test world = $(cat hello)
 	)
 '

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 53213f9a3b9..0a9e25a57f8 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -303,6 +303,58 @@ static int add_directory_to_archiver(struct strvec *archiver_args,
 	return res;
 }
 
+#ifndef WIN32
+#include <sys/statvfs.h>
+#endif
+
+static int get_disk_info(struct strbuf *out)
+{
+#ifdef WIN32
+	struct strbuf buf = STRBUF_INIT;
+	char volume_name[MAX_PATH], fs_name[MAX_PATH];
+	DWORD serial_number, component_length, flags;
+	ULARGE_INTEGER avail2caller, total, avail;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (!GetDiskFreeSpaceExA(buf.buf, &avail2caller, &total, &avail)) {
+		error(_("could not determine free disk size for '%s'"),
+		      buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_setlen(&buf, offset_1st_component(buf.buf));
+	if (!GetVolumeInformationA(buf.buf, volume_name, sizeof(volume_name),
+				   &serial_number, &component_length, &flags,
+				   fs_name, sizeof(fs_name))) {
+		error(_("could not get info for '%s'"), buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, avail2caller.QuadPart);
+	strbuf_addch(out, '\n');
+	strbuf_release(&buf);
+#else
+	struct strbuf buf = STRBUF_INIT;
+	struct statvfs stat;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (statvfs(buf.buf, &stat) < 0) {
+		error_errno(_("could not determine free disk size for '%s'"),
+			    buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, st_mult(stat.f_bsize, stat.f_bavail));
+	strbuf_addf(out, " (mount flags 0x%lx)\n", stat.f_flag);
+	strbuf_release(&buf);
+#endif
+	return 0;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -599,6 +651,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	get_version_info(&buf, 1);
 
 	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	get_disk_info(&buf);
 	write_or_die(stdout_fd, buf.buf, buf.len);
 	strvec_pushf(&archiver_args,
 		     "--add-virtual-file=diagnostics.log:%.*s",
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 6802d317258..934b2485d91 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -94,6 +94,7 @@ SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	scalar diagnose cloned >out 2>err &&
+	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
 	zip_path=$(cat zip_path) &&
 	test -n "$zip_path" &&

contrib/scalar/scalar.c, contrib/scalar/scalar.txt, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 00dcd4b50ef..53213f9a3b9 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -11,6 +11,7 @@
 #include "dir.h"
 #include "packfile.h"
 #include "help.h"
+#include "archive.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -261,6 +262,47 @@ static int unregister_dir(void)
 	return res;
 }
 
+static int add_directory_to_archiver(struct strvec *archiver_args,
+					  const char *path, int recurse)
+{
+	int at_root = !*path;
+	DIR *dir = opendir(at_root ? "." : path);
+	struct dirent *e;
+	struct strbuf buf = STRBUF_INIT;
+	size_t len;
+	int res = 0;
+
+	if (!dir)
+		return error_errno(_("could not open directory '%s'"), path);
+
+	if (!at_root)
+		strbuf_addf(&buf, "%s/", path);
+	len = buf.len;
+	strvec_pushf(archiver_args, "--prefix=%s", buf.buf);
+
+	while (!res && (e = readdir(dir))) {
+		if (!strcmp(".", e->d_name) || !strcmp("..", e->d_name))
+			continue;
+
+		strbuf_setlen(&buf, len);
+		strbuf_addstr(&buf, e->d_name);
+
+		if (e->d_type == DT_REG)
+			strvec_pushf(archiver_args, "--add-file=%s", buf.buf);
+		else if (e->d_type != DT_DIR)
+			warning(_("skipping '%s', which is neither file nor "
+				  "directory"), buf.buf);
+		else if (recurse &&
+			 add_directory_to_archiver(archiver_args,
+						   buf.buf, recurse) < 0)
+			res = -1;
+	}
+
+	closedir(dir);
+	strbuf_release(&buf);
+	return res;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -501,6 +543,107 @@ cleanup:
 	return res;
 }
 
+static int cmd_diagnose(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		N_("scalar diagnose [<enlistment>]"),
+		NULL
+	};
+	struct strbuf zip_path = STRBUF_INIT;
+	struct strvec archiver_args = STRVEC_INIT;
+	char **argv_copy = NULL;
+	int stdout_fd = -1, archiver_fd = -1;
+	time_t now = time(NULL);
+	struct tm tm;
+	struct strbuf path = STRBUF_INIT, buf = STRBUF_INIT;
+	int res = 0;
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	setup_enlistment_directory(argc, argv, usage, options, &zip_path);
+
+	strbuf_addstr(&zip_path, "/.scalarDiagnostics/scalar_");
+	strbuf_addftime(&zip_path,
+			"%Y%m%d_%H%M%S", localtime_r(&now, &tm), 0, 0);
+	strbuf_addstr(&zip_path, ".zip");
+	switch (safe_create_leading_directories(zip_path.buf)) {
+	case SCLD_EXISTS:
+	case SCLD_OK:
+		break;
+	default:
+		error_errno(_("could not create directory for '%s'"),
+			    zip_path.buf);
+		goto diagnose_cleanup;
+	}
+	stdout_fd = dup(1);
+	if (stdout_fd < 0) {
+		res = error_errno(_("could not duplicate stdout"));
+		goto diagnose_cleanup;
+	}
+
+	archiver_fd = xopen(zip_path.buf, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+	if (archiver_fd < 0 || dup2(archiver_fd, 1) < 0) {
+		res = error_errno(_("could not redirect output"));
+		goto diagnose_cleanup;
+	}
+
+	init_zip_archiver();
+	strvec_pushl(&archiver_args, "scalar-diagnose", "--format=zip", NULL);
+
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "Collecting diagnostic info\n\n");
+	get_version_info(&buf, 1);
+
+	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	write_or_die(stdout_fd, buf.buf, buf.len);
+	strvec_pushf(&archiver_args,
+		     "--add-virtual-file=diagnostics.log:%.*s",
+		     (int)buf.len, buf.buf);
+
+	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/logs", 1)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/objects/info", 0)))
+		goto diagnose_cleanup;
+
+	strvec_pushl(&archiver_args, "--prefix=",
+		     oid_to_hex(the_hash_algo->empty_tree), "--", NULL);
+
+	/* `write_archive()` modifies the `argv` passed to it. Let it. */
+	argv_copy = xmemdupz(archiver_args.v,
+			     sizeof(char *) * archiver_args.nr);
+	res = write_archive(archiver_args.nr, (const char **)argv_copy, NULL,
+			    the_repository, NULL, 0);
+	if (res) {
+		error(_("failed to write archive"));
+		goto diagnose_cleanup;
+	}
+
+	if (!res)
+		fprintf(stderr, "\n"
+		       "Diagnostics complete.\n"
+		       "All of the gathered info is captured in '%s'\n",
+		       zip_path.buf);
+
+diagnose_cleanup:
+	if (archiver_fd >= 0) {
+		close(1);
+		dup2(stdout_fd, 1);
+	}
+	free(argv_copy);
+	strvec_clear(&archiver_args);
+	strbuf_release(&zip_path);
+	strbuf_release(&path);
+	strbuf_release(&buf);
+
+	return res;
+}
+
 static int cmd_list(int argc, const char **argv)
 {
 	if (argc != 1)
@@ -802,6 +945,7 @@ static struct {
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
 	{ "version", cmd_version },
+	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
 };
 
diff --git a/contrib/scalar/scalar.txt b/contrib/scalar/scalar.txt
index f416d637289..22583fe046e 100644
--- a/contrib/scalar/scalar.txt
+++ b/contrib/scalar/scalar.txt
@@ -14,6 +14,7 @@ scalar register [<enlistment>]
 scalar unregister [<enlistment>]
 scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
 scalar reconfigure [ --all | <enlistment> ]
+scalar diagnose [<enlistment>]
 scalar delete <enlistment>
 
 DESCRIPTION
@@ -129,6 +130,17 @@ reconfigure the enlistment.
 With the `--all` option, all enlistments currently registered with Scalar
 will be reconfigured. Use this option after each Scalar upgrade.
 
+Diagnose
+~~~~~~~~
+
+diagnose [<enlistment>]::
+    When reporting issues with Scalar, it is often helpful to provide the
+    information gathered by this command, including logs and certain
+    statistics describing the data shape of the current enlistment.
++
+The output of this command is a `.zip` file that is written into
+a directory adjacent to the worktree in the `src` directory.
+
 Delete
 ~~~~~~
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 9d83fdf25e8..6802d317258 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -90,4 +90,18 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 	grep "cloned. does not exist" err
 '
 
+SQ="'"
+test_expect_success UNZIP 'scalar diagnose' '
+	scalar clone "file://$(pwd)" cloned --single-branch &&
+	scalar diagnose cloned >out 2>err &&
+	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
+	zip_path=$(cat zip_path) &&
+	test -n "$zip_path" &&
+	unzip -v "$zip_path" &&
+	folder=${zip_path%.zip} &&
+	test_path_is_missing "$folder" &&
+	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out
+'
+
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 1ce9c2b00e8..00dcd4b50ef 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -43,9 +43,11 @@ static void setup_enlistment_directory(int argc, const char **argv,
 		usage_with_options(usagestr, options);
 
 	/* find the worktree, determine its corresponding root */
-	if (argc == 1)
+	if (argc == 1) {
 		strbuf_add_absolute_path(&path, argv[0]);
-	else if (strbuf_getcwd(&path) < 0)
+		if (!is_directory(path.buf))
+			die(_("'%s' does not exist"), path.buf);
+	} else if (strbuf_getcwd(&path) < 0)
 		die(_("need a working directory"));
 
 	strbuf_trim_trailing_dir_sep(&path);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 2e1502ad45e..9d83fdf25e8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -85,4 +85,9 @@ test_expect_success 'scalar delete with enlistment' '
 	test_path_is_missing cloned
 '
 
+test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
+	! scalar run config cloned 2>err &&
+	grep "cloned. does not exist" err
+'
+
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 0a9e25a57f8..d302c27e114 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "help.h"
 #include "archive.h"
+#include "object-store.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -595,6 +596,29 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats_objects(const char *full_path, size_t full_path_len,
+				   const char *file_name, void *data)
+{
+	struct strbuf *buf = data;
+	struct stat st;
+
+	if (!stat(full_path, &st))
+		strbuf_addf(buf, "%-70s %16" PRIuMAX "\n", file_name,
+			    (uintmax_t)st.st_size);
+}
+
+static int dir_file_stats(struct object_directory *object_dir, void *data)
+{
+	struct strbuf *buf = data;
+
+	strbuf_addf(buf, "Contents of %s:\n", object_dir->path);
+
+	for_each_file_in_pack_dir(object_dir->path, dir_file_stats_objects,
+				  data);
+
+	return 0;
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -657,6 +681,12 @@ static int cmd_diagnose(int argc, const char **argv)
 		     "--add-virtual-file=diagnostics.log:%.*s",
 		     (int)buf.len, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-virtual-file=packs-local.txt:");
+	dir_file_stats(the_repository->objects->odb, &buf);
+	foreach_alt_odb(dir_file_stats, &buf);
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 934b2485d91..3dd5650cceb 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -93,6 +93,8 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
+	git repack &&
+	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -102,7 +104,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
-	test_file_not_empty out
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
+	grep "$(pwd)/.git/objects" out
 '
 
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index d302c27e114..0c278681758 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -619,6 +619,60 @@ static int dir_file_stats(struct object_directory *object_dir, void *data)
 	return 0;
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -687,6 +741,11 @@ static int cmd_diagnose(int argc, const char **argv)
 	foreach_alt_odb(dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-virtual-file=objects-local.txt:");
+	loose_objs_stats(&buf, ".git/objects");
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 3dd5650cceb..72023a1ca1d 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -95,6 +95,7 @@ test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	git repack &&
 	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
+	test_commit -C cloned/src loose &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -106,7 +107,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
-	grep "$(pwd)/.git/objects" out
+	grep "$(pwd)/.git/objects" out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
+	grep "^Total: [1-9]" out
 '
 
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a7834..893cb1075bf 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -61,6 +61,17 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 
+--add-virtual-file=<path>:<content>::
+	Add the specified contents to the archive.  Can be repeated to add
+	multiple files.  The path of the file in the archive is built
+	by concatenating the value for `--prefix` (if any) and the
+	basename of <file>.
++
+The `<path>` cannot contain any colon, the file mode is limited to
+a regular file, and the option may be subject to platform-dependent
+command-line limits. For non-trivial cases, write an untracked file
+and use `--add-file` instead.
+
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
 	as well (see <<ATTRIBUTES>>).
diff --git a/archive.c b/archive.c
index a3bbb091256..d20e16fa819 100644
--- a/archive.c
+++ b/archive.c
@@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 struct extra_file_info {
 	char *base;
 	struct stat stat;
+	void *content;
 };
 
 int write_archive_entries(struct archiver_args *args,
@@ -337,7 +338,13 @@ int write_archive_entries(struct archiver_args *args,
 		strbuf_addstr(&path_in_archive, basename(path));
 
 		strbuf_reset(&content);
-		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
+		if (info->content)
+			err = write_entry(args, &fake_oid, path_in_archive.buf,
+					  path_in_archive.len,
+					  info->stat.st_mode,
+					  info->content, info->stat.st_size);
+		else if (strbuf_read_file(&content, path,
+					  info->stat.st_size) < 0)
 			err = error_errno(_("could not read '%s'"), path);
 		else
 			err = write_entry(args, &fake_oid, path_in_archive.buf,
@@ -493,6 +500,7 @@ static void extra_file_info_clear(void *util, const char *str)
 {
 	struct extra_file_info *info = util;
 	free(info->base);
+	free(info->content);
 	free(info);
 }
 
@@ -514,14 +522,40 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	if (!arg)
 		return -1;
 
-	path = prefix_filename(args->prefix, arg);
-	item = string_list_append_nodup(&args->extra_files, path);
-	item->util = info = xmalloc(sizeof(*info));
+	info = xmalloc(sizeof(*info));
 	info->base = xstrdup_or_null(base);
-	if (stat(path, &info->stat))
-		die(_("File not found: %s"), path);
-	if (!S_ISREG(info->stat.st_mode))
-		die(_("Not a regular file: %s"), path);
+
+	if (!strcmp(opt->long_name, "add-file")) {
+		path = prefix_filename(args->prefix, arg);
+		if (stat(path, &info->stat))
+			die(_("File not found: %s"), path);
+		if (!S_ISREG(info->stat.st_mode))
+			die(_("Not a regular file: %s"), path);
+		info->content = NULL; /* read the file later */
+	} else if (!strcmp(opt->long_name, "add-virtual-file")) {
+		const char *colon = strchr(arg, ':');
+		char *p;
+
+		if (!colon)
+			die(_("missing colon: '%s'"), arg);
+
+		p = xstrndup(arg, colon - arg);
+		if (!args->prefix)
+			path = p;
+		else {
+			path = prefix_filename(args->prefix, p);
+			free(p);
+		}
+		memset(&info->stat, 0, sizeof(info->stat));
+		info->stat.st_mode = S_IFREG | 0644;
+		info->content = xstrdup(colon + 1);
+		info->stat.st_size = strlen(info->content);
+	} else {
+		BUG("add_file_cb() called for %s", opt->long_name);
+	}
+	item = string_list_append_nodup(&args->extra_files, path);
+	item->util = info;
+
 	return 0;
 }
 
@@ -554,6 +588,9 @@ static int parse_archive_args(int argc, const char **argv,
 		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
 		  N_("add untracked file to archive"), 0, add_file_cb,
 		  (intptr_t)&base },
+		{ OPTION_CALLBACK, 0, "add-virtual-file", args,
+		  N_("path:content"), N_("add untracked file to archive"), 0,
+		  add_file_cb, (intptr_t)&base },
 		OPT_STRING('o', "output", &output, N_("file"),
 			N_("write the archive to this file")),
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 1e6d18b140e..ebc26e89a9b 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -206,6 +206,18 @@ test_expect_success 'git archive --format=zip --add-file' '
 check_zip with_untracked
 check_added with_untracked untracked untracked
 
+test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
+	git archive --format=zip >with_file_with_content.zip \
+		--add-virtual-file=hello:world $EMPTY_TREE &&
+	test_when_finished "rm -rf tmp-unpack" &&
+	mkdir tmp-unpack && (
+		cd tmp-unpack &&
+		"$GIT_UNZIP" ../with_file_with_content.zip &&
+		test_path_is_file hello &&
+		test world = $(cat hello)
+	)
+'
+
 test_expect_success 'git archive --format=zip --add-file twice' '
 	echo untracked >untracked &&
 	git archive --format=zip --prefix=one/ --add-file=untracked \

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a783..10a48ab5f8 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -49,7 +49,9 @@ OPTIONS
 	Report progress to stderr.

 --prefix=<prefix>/::
-	Prepend <prefix>/ to each filename in the archive.
+	Prepend <prefix>/ to each filename in the archive.  Can be
+	specified multiple times; the last one seen when reading from
+	left to right is applied.

 -o <file>::
 --output=<file>::
@@ -58,8 +60,8 @@ OPTIONS
 --add-file=<file>::
 	Add a non-tracked file to the archive.  Can be repeated to add
 	multiple files.  The path of the file in the archive is built
-	by concatenating the value for `--prefix` (if any) and the
-	basename of <file>.
+	by concatenating the current value for `--prefix` (if any) and
+	the basename of <file>.

 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
@@ -194,6 +196,12 @@ EXAMPLES
 	commit on the current branch. Note that the output format is
 	inferred by the extension of the output file.

+`git archive -o latest.tar --prefix=build/ --add-file=configure --prefix= HEAD`::
+
+	Creates a tar archive that contains the contents of the latest
+	commit on the current branch with no prefix and the untracked
+	file 'configure' with the prefix 'build/'.
+
 `git config tar.tar.xz.command "xz -c"`::

 	Configure a "tar.xz" format for making LZMA-compressed tarfiles.
--
2.35.3

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a783..9c0e306c03 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -49,7 +49,9 @@ OPTIONS
 	Report progress to stderr.

 --prefix=<prefix>/::
-	Prepend <prefix>/ to each filename in the archive.
+	Prepend <prefix>/ to paths in the archive.  Can be repeated; its
+	leftmost value is used for all tracked files.  See below which
+	value gets used by `--add-file`.

 -o <file>::
 --output=<file>::
@@ -58,8 +60,9 @@ OPTIONS
 --add-file=<file>::
 	Add a non-tracked file to the archive.  Can be repeated to add
 	multiple files.  The path of the file in the archive is built
-	by concatenating the value for `--prefix` (if any) and the
-	basename of <file>.
+	by concatenating the value of the leftmost `--prefix` option to
+	the right of this `--add-file` (if any) and the basename of
+	<file>.

 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
@@ -194,6 +197,12 @@ EXAMPLES
 	commit on the current branch. Note that the output format is
 	inferred by the extension of the output file.

+`git archive -o latest.tar --prefix=build/ --add-file=configure --prefix= HEAD`::
+
+	Creates a tar archive that contains the contents of the latest
+	commit on the current branch with no prefix and the untracked
+	file 'configure' with the prefix 'build/'.
+
 `git config tar.tar.xz.command "xz -c"`::

 	Configure a "tar.xz" format for making LZMA-compressed tarfiles.
--
2.35.3

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index bc4e76a783..94519aae23 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -49,7 +49,9 @@ OPTIONS
 	Report progress to stderr.

 --prefix=<prefix>/::
-	Prepend <prefix>/ to each filename in the archive.
+	Prepend <prefix>/ to paths in the archive.  Can be repeated; its
+	rightmost value is used for all tracked files.  See below which
+	value gets used by `--add-file`.

 -o <file>::
 --output=<file>::
@@ -57,9 +59,9 @@ OPTIONS

 --add-file=<file>::
 	Add a non-tracked file to the archive.  Can be repeated to add
-	multiple files.  The path of the file in the archive is built
-	by concatenating the value for `--prefix` (if any) and the
-	basename of <file>.
+	multiple files.  The path of the file in the archive is built by
+	concatenating the value of the last `--prefix` option (if any)
+	before this `--add-file` and the basename of <file>.

 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
@@ -194,6 +196,12 @@ EXAMPLES
 	commit on the current branch. Note that the output format is
 	inferred by the extension of the output file.

+`git archive -o latest.tar --prefix=build/ --add-file=configure --prefix= HEAD`::
+
+	Creates a tar archive that contains the contents of the latest
+	commit on the current branch with no prefix and the untracked
+	file 'configure' with the prefix 'build/'.
+
 `git config tar.tar.xz.command "xz -c"`::

 	Configure a "tar.xz" format for making LZMA-compressed tarfiles.
--
2.35.3

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 1ce9c2b00e8..00dcd4b50ef 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -43,9 +43,11 @@ static void setup_enlistment_directory(int argc, const char **argv,
 		usage_with_options(usagestr, options);
 
 	/* find the worktree, determine its corresponding root */
-	if (argc == 1)
+	if (argc == 1) {
 		strbuf_add_absolute_path(&path, argv[0]);
-	else if (strbuf_getcwd(&path) < 0)
+		if (!is_directory(path.buf))
+			die(_("'%s' does not exist"), path.buf);
+	} else if (strbuf_getcwd(&path) < 0)
 		die(_("need a working directory"));
 
 	strbuf_trim_trailing_dir_sep(&path);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 2e1502ad45e..9d83fdf25e8 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -85,4 +85,9 @@ test_expect_success 'scalar delete with enlistment' '
 	test_path_is_missing cloned
 '
 
+test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
+	! scalar run config cloned 2>err &&
+	grep "cloned. does not exist" err
+'
+
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index 893cb1075bf..54de945a84e 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -67,10 +67,16 @@ OPTIONS
 	by concatenating the value for `--prefix` (if any) and the
 	basename of <file>.
 +
-The `<path>` cannot contain any colon, the file mode is limited to
-a regular file, and the option may be subject to platform-dependent
-command-line limits. For non-trivial cases, write an untracked file
-and use `--add-file` instead.
+The `<path>` argument can start and end with a literal double-quote
+character; The contained file name is interpreted as a C-style string,
+i.e. the backslash is interpreted as escape character. The path must
+be quoted if it contains a colon, to avoid the colon from being
+misinterpreted as the separator between the path and the contents, or
+if the path begins or ends with a double-quote character.
++
+The file mode is limited to a regular file, and the option may be
+subject to platform-dependent command-line limits. For non-trivial
+cases, write an untracked file and use `--add-file` instead.
 
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
diff --git a/archive.c b/archive.c
index d20e16fa819..b7756b91200 100644
--- a/archive.c
+++ b/archive.c
@@ -9,6 +9,7 @@
 #include "parse-options.h"
 #include "unpack-trees.h"
 #include "dir.h"
+#include "quote.h"
 
 static char const * const archive_usage[] = {
 	N_("git archive [<options>] <tree-ish> [<path>...]"),
@@ -533,22 +534,31 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 			die(_("Not a regular file: %s"), path);
 		info->content = NULL; /* read the file later */
 	} else if (!strcmp(opt->long_name, "add-virtual-file")) {
-		const char *colon = strchr(arg, ':');
-		char *p;
+		struct strbuf buf = STRBUF_INIT;
+		const char *p = arg;
+
+		if (*p != '"')
+			p = strchr(p, ':');
+		else if (unquote_c_style(&buf, p, &p) < 0)
+			die(_("unclosed quote: '%s'"), arg);
 
-		if (!colon)
+		if (!p || *p != ':')
 			die(_("missing colon: '%s'"), arg);
 
-		p = xstrndup(arg, colon - arg);
-		if (!args->prefix)
-			path = p;
-		else {
-			path = prefix_filename(args->prefix, p);
-			free(p);
+		if (p == arg)
+			die(_("empty file name: '%s'"), arg);
+
+		path = buf.len ?
+			strbuf_detach(&buf, NULL) : xstrndup(arg, p - arg);
+
+		if (args->prefix) {
+			char *save = path;
+			path = prefix_filename(args->prefix, path);
+			free(save);
 		}
 		memset(&info->stat, 0, sizeof(info->stat));
 		info->stat.st_mode = S_IFREG | 0644;
-		info->content = xstrdup(colon + 1);
+		info->content = xstrdup(p + 1);
 		info->stat.st_size = strlen(info->content);
 	} else {
 		BUG("add_file_cb() called for %s", opt->long_name);
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index ebc26e89a9b..3a5a052e8ce 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -207,13 +207,21 @@ check_zip with_untracked
 check_added with_untracked untracked untracked
 
 test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
+	if test_have_prereq FUNNYNAMES
+	then
+		PATHNAME=quoted:colon
+	else
+		PATHNAME=quoted
+	fi &&
 	git archive --format=zip >with_file_with_content.zip \
+		--add-virtual-file=\"$PATHNAME\": \
 		--add-virtual-file=hello:world $EMPTY_TREE &&
 	test_when_finished "rm -rf tmp-unpack" &&
 	mkdir tmp-unpack && (
 		cd tmp-unpack &&
 		"$GIT_UNZIP" ../with_file_with_content.zip &&
 		test_path_is_file hello &&
+		test_path_is_file $PATHNAME &&
 		test world = $(cat hello)
 	)
 '

diff --git c/t/t5003-archive-zip.sh w/t/t5003-archive-zip.sh
index 3a5a052e8c..6addb6c684 100755
--- c/t/t5003-archive-zip.sh
+++ w/t/t5003-archive-zip.sh
@@ -209,19 +209,19 @@ check_added with_untracked untracked untracked
 test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
 	if test_have_prereq FUNNYNAMES
 	then
-		PATHNAME=quoted:colon
+		PATHNAME="pathname with : colon"
 	else
-		PATHNAME=quoted
+		PATHNAME="pathname without colon"
 	fi &&
 	git archive --format=zip >with_file_with_content.zip \
-		--add-virtual-file=\"$PATHNAME\": \
+		--add-virtual-file=\""$PATHNAME"\": \
 		--add-virtual-file=hello:world $EMPTY_TREE &&
 	test_when_finished "rm -rf tmp-unpack" &&
 	mkdir tmp-unpack && (
 		cd tmp-unpack &&
 		"$GIT_UNZIP" ../with_file_with_content.zip &&
 		test_path_is_file hello &&
-		test_path_is_file $PATHNAME &&
+		test_path_is_file "$PATHNAME" &&
 		test world = $(cat hello)
 	)
 '

diff --git c/Makefile w/Makefile
index 298becd5a5..1d544ad46a 100644
--- c/Makefile
+++ w/Makefile
@@ -749,6 +749,7 @@ TEST_BUILTINS_OBJS += test-pkt-line.o
 TEST_BUILTINS_OBJS += test-prio-queue.o
 TEST_BUILTINS_OBJS += test-proc-receive.o
 TEST_BUILTINS_OBJS += test-progress.o
+TEST_BUILTINS_OBJS += test-quoted.o
 TEST_BUILTINS_OBJS += test-reach.o
 TEST_BUILTINS_OBJS += test-read-cache.o
 TEST_BUILTINS_OBJS += test-read-graph.o
diff --git c/t/helper/test-quoted.c w/t/helper/test-quoted.c
new file mode 100644
index 0000000000..15baa55e43
--- /dev/null
+++ w/t/helper/test-quoted.c
@@ -0,0 +1,34 @@
+#include "test-tool.h"
+#include "cache.h"
+#include "quote.h"
+
+int cmd__unquote_c_style(int argc, const char **argv)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	while (*++argv) {
+		const char *p = *argv;
+
+		if (unquote_c_style(&buf, p, &p) < 0)
+			error("cannot unquote '%s'", *argv);
+		else
+			printf("%s\n", buf.buf);
+		strbuf_reset(&buf);
+	}
+	return 0;
+}
+
+int cmd__quote_c_style(int argc, const char **argv)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	while (*++argv) {
+		const char *p = *argv;
+
+		quote_c_style(p, &buf, NULL, 0);
+		printf("%s\n", buf.buf);
+		strbuf_reset(&buf);
+	}
+	return 0;
+}
+
diff --git c/t/helper/test-tool.c w/t/helper/test-tool.c
index d2eacd302d..5633c98569 100644
--- c/t/helper/test-tool.c
+++ w/t/helper/test-tool.c
@@ -58,6 +58,7 @@ static struct test_cmd cmds[] = {
 	{ "prio-queue", cmd__prio_queue },
 	{ "proc-receive", cmd__proc_receive },
 	{ "progress", cmd__progress },
+	{ "quote-c-style", cmd__quote_c_style },
 	{ "reach", cmd__reach },
 	{ "read-cache", cmd__read_cache },
 	{ "read-graph", cmd__read_graph },
@@ -81,6 +82,7 @@ static struct test_cmd cmds[] = {
 	{ "submodule-nested-repo-config", cmd__submodule_nested_repo_config },
 	{ "subprocess", cmd__subprocess },
 	{ "trace2", cmd__trace2 },
+	{ "unquote-c-style", cmd__unquote_c_style },
 	{ "userdiff", cmd__userdiff },
 	{ "urlmatch-normalization", cmd__urlmatch_normalization },
 	{ "xml-encode", cmd__xml_encode },
diff --git c/t/helper/test-tool.h w/t/helper/test-tool.h
index 960cc27ef7..f5e8929009 100644
--- c/t/helper/test-tool.h
+++ w/t/helper/test-tool.h
@@ -48,6 +48,7 @@ int cmd__pkt_line(int argc, const char **argv);
 int cmd__prio_queue(int argc, const char **argv);
 int cmd__proc_receive(int argc, const char **argv);
 int cmd__progress(int argc, const char **argv);
+int cmd__quote_c_style(int argc, const char **argv);
 int cmd__reach(int argc, const char **argv);
 int cmd__read_cache(int argc, const char **argv);
 int cmd__read_graph(int argc, const char **argv);
@@ -71,6 +72,7 @@ int cmd__submodule_config(int argc, const char **argv);
 int cmd__submodule_nested_repo_config(int argc, const char **argv);
 int cmd__subprocess(int argc, const char **argv);
 int cmd__trace2(int argc, const char **argv);
+int cmd__unquote_c_style(int argc, const char **argv);
 int cmd__userdiff(int argc, const char **argv);
 int cmd__urlmatch_normalization(int argc, const char **argv);
 int cmd__xml_encode(int argc, const char **argv);

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 0a9e25a57f8..d302c27e114 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "help.h"
 #include "archive.h"
+#include "object-store.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -595,6 +596,29 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats_objects(const char *full_path, size_t full_path_len,
+				   const char *file_name, void *data)
+{
+	struct strbuf *buf = data;
+	struct stat st;
+
+	if (!stat(full_path, &st))
+		strbuf_addf(buf, "%-70s %16" PRIuMAX "\n", file_name,
+			    (uintmax_t)st.st_size);
+}
+
+static int dir_file_stats(struct object_directory *object_dir, void *data)
+{
+	struct strbuf *buf = data;
+
+	strbuf_addf(buf, "Contents of %s:\n", object_dir->path);
+
+	for_each_file_in_pack_dir(object_dir->path, dir_file_stats_objects,
+				  data);
+
+	return 0;
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -657,6 +681,12 @@ static int cmd_diagnose(int argc, const char **argv)
 		     "--add-virtual-file=diagnostics.log:%.*s",
 		     (int)buf.len, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-virtual-file=packs-local.txt:");
+	dir_file_stats(the_repository->objects->odb, &buf);
+	foreach_alt_odb(dir_file_stats, &buf);
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 934b2485d91..3dd5650cceb 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -93,6 +93,8 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
+	git repack &&
+	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -102,7 +104,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
-	test_file_not_empty out
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
+	grep "$(pwd)/.git/objects" out
 '
 
 test_done

contrib/scalar/scalar.c, contrib/scalar/scalar.txt, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 00dcd4b50ef..53213f9a3b9 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -11,6 +11,7 @@
 #include "dir.h"
 #include "packfile.h"
 #include "help.h"
+#include "archive.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -261,6 +262,47 @@ static int unregister_dir(void)
 	return res;
 }
 
+static int add_directory_to_archiver(struct strvec *archiver_args,
+					  const char *path, int recurse)
+{
+	int at_root = !*path;
+	DIR *dir = opendir(at_root ? "." : path);
+	struct dirent *e;
+	struct strbuf buf = STRBUF_INIT;
+	size_t len;
+	int res = 0;
+
+	if (!dir)
+		return error_errno(_("could not open directory '%s'"), path);
+
+	if (!at_root)
+		strbuf_addf(&buf, "%s/", path);
+	len = buf.len;
+	strvec_pushf(archiver_args, "--prefix=%s", buf.buf);
+
+	while (!res && (e = readdir(dir))) {
+		if (!strcmp(".", e->d_name) || !strcmp("..", e->d_name))
+			continue;
+
+		strbuf_setlen(&buf, len);
+		strbuf_addstr(&buf, e->d_name);
+
+		if (e->d_type == DT_REG)
+			strvec_pushf(archiver_args, "--add-file=%s", buf.buf);
+		else if (e->d_type != DT_DIR)
+			warning(_("skipping '%s', which is neither file nor "
+				  "directory"), buf.buf);
+		else if (recurse &&
+			 add_directory_to_archiver(archiver_args,
+						   buf.buf, recurse) < 0)
+			res = -1;
+	}
+
+	closedir(dir);
+	strbuf_release(&buf);
+	return res;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -501,6 +543,107 @@ cleanup:
 	return res;
 }
 
+static int cmd_diagnose(int argc, const char **argv)
+{
+	struct option options[] = {
+		OPT_END(),
+	};
+	const char * const usage[] = {
+		N_("scalar diagnose [<enlistment>]"),
+		NULL
+	};
+	struct strbuf zip_path = STRBUF_INIT;
+	struct strvec archiver_args = STRVEC_INIT;
+	char **argv_copy = NULL;
+	int stdout_fd = -1, archiver_fd = -1;
+	time_t now = time(NULL);
+	struct tm tm;
+	struct strbuf path = STRBUF_INIT, buf = STRBUF_INIT;
+	int res = 0;
+
+	argc = parse_options(argc, argv, NULL, options,
+			     usage, 0);
+
+	setup_enlistment_directory(argc, argv, usage, options, &zip_path);
+
+	strbuf_addstr(&zip_path, "/.scalarDiagnostics/scalar_");
+	strbuf_addftime(&zip_path,
+			"%Y%m%d_%H%M%S", localtime_r(&now, &tm), 0, 0);
+	strbuf_addstr(&zip_path, ".zip");
+	switch (safe_create_leading_directories(zip_path.buf)) {
+	case SCLD_EXISTS:
+	case SCLD_OK:
+		break;
+	default:
+		error_errno(_("could not create directory for '%s'"),
+			    zip_path.buf);
+		goto diagnose_cleanup;
+	}
+	stdout_fd = dup(1);
+	if (stdout_fd < 0) {
+		res = error_errno(_("could not duplicate stdout"));
+		goto diagnose_cleanup;
+	}
+
+	archiver_fd = xopen(zip_path.buf, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+	if (archiver_fd < 0 || dup2(archiver_fd, 1) < 0) {
+		res = error_errno(_("could not redirect output"));
+		goto diagnose_cleanup;
+	}
+
+	init_zip_archiver();
+	strvec_pushl(&archiver_args, "scalar-diagnose", "--format=zip", NULL);
+
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "Collecting diagnostic info\n\n");
+	get_version_info(&buf, 1);
+
+	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	write_or_die(stdout_fd, buf.buf, buf.len);
+	strvec_pushf(&archiver_args,
+		     "--add-virtual-file=diagnostics.log:%.*s",
+		     (int)buf.len, buf.buf);
+
+	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/logs", 1)) ||
+	    (res = add_directory_to_archiver(&archiver_args, ".git/objects/info", 0)))
+		goto diagnose_cleanup;
+
+	strvec_pushl(&archiver_args, "--prefix=",
+		     oid_to_hex(the_hash_algo->empty_tree), "--", NULL);
+
+	/* `write_archive()` modifies the `argv` passed to it. Let it. */
+	argv_copy = xmemdupz(archiver_args.v,
+			     sizeof(char *) * archiver_args.nr);
+	res = write_archive(archiver_args.nr, (const char **)argv_copy, NULL,
+			    the_repository, NULL, 0);
+	if (res) {
+		error(_("failed to write archive"));
+		goto diagnose_cleanup;
+	}
+
+	if (!res)
+		fprintf(stderr, "\n"
+		       "Diagnostics complete.\n"
+		       "All of the gathered info is captured in '%s'\n",
+		       zip_path.buf);
+
+diagnose_cleanup:
+	if (archiver_fd >= 0) {
+		close(1);
+		dup2(stdout_fd, 1);
+	}
+	free(argv_copy);
+	strvec_clear(&archiver_args);
+	strbuf_release(&zip_path);
+	strbuf_release(&path);
+	strbuf_release(&buf);
+
+	return res;
+}
+
 static int cmd_list(int argc, const char **argv)
 {
 	if (argc != 1)
@@ -802,6 +945,7 @@ static struct {
 	{ "reconfigure", cmd_reconfigure },
 	{ "delete", cmd_delete },
 	{ "version", cmd_version },
+	{ "diagnose", cmd_diagnose },
 	{ NULL, NULL},
 };
 
diff --git a/contrib/scalar/scalar.txt b/contrib/scalar/scalar.txt
index f416d637289..22583fe046e 100644
--- a/contrib/scalar/scalar.txt
+++ b/contrib/scalar/scalar.txt
@@ -14,6 +14,7 @@ scalar register [<enlistment>]
 scalar unregister [<enlistment>]
 scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
 scalar reconfigure [ --all | <enlistment> ]
+scalar diagnose [<enlistment>]
 scalar delete <enlistment>
 
 DESCRIPTION
@@ -129,6 +130,17 @@ reconfigure the enlistment.
 With the `--all` option, all enlistments currently registered with Scalar
 will be reconfigured. Use this option after each Scalar upgrade.
 
+Diagnose
+~~~~~~~~
+
+diagnose [<enlistment>]::
+    When reporting issues with Scalar, it is often helpful to provide the
+    information gathered by this command, including logs and certain
+    statistics describing the data shape of the current enlistment.
++
+The output of this command is a `.zip` file that is written into
+a directory adjacent to the worktree in the `src` directory.
+
 Delete
 ~~~~~~
 
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 9d83fdf25e8..6802d317258 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -90,4 +90,18 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 	grep "cloned. does not exist" err
 '
 
+SQ="'"
+test_expect_success UNZIP 'scalar diagnose' '
+	scalar clone "file://$(pwd)" cloned --single-branch &&
+	scalar diagnose cloned >out 2>err &&
+	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
+	zip_path=$(cat zip_path) &&
+	test -n "$zip_path" &&
+	unzip -v "$zip_path" &&
+	folder=${zip_path%.zip} &&
+	test_path_is_missing "$folder" &&
+	unzip -p "$zip_path" diagnostics.log >out &&
+	test_file_not_empty out
+'
+
 test_done

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 53213f9a3b9..0a9e25a57f8 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -303,6 +303,58 @@ static int add_directory_to_archiver(struct strvec *archiver_args,
 	return res;
 }
 
+#ifndef WIN32
+#include <sys/statvfs.h>
+#endif
+
+static int get_disk_info(struct strbuf *out)
+{
+#ifdef WIN32
+	struct strbuf buf = STRBUF_INIT;
+	char volume_name[MAX_PATH], fs_name[MAX_PATH];
+	DWORD serial_number, component_length, flags;
+	ULARGE_INTEGER avail2caller, total, avail;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (!GetDiskFreeSpaceExA(buf.buf, &avail2caller, &total, &avail)) {
+		error(_("could not determine free disk size for '%s'"),
+		      buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_setlen(&buf, offset_1st_component(buf.buf));
+	if (!GetVolumeInformationA(buf.buf, volume_name, sizeof(volume_name),
+				   &serial_number, &component_length, &flags,
+				   fs_name, sizeof(fs_name))) {
+		error(_("could not get info for '%s'"), buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, avail2caller.QuadPart);
+	strbuf_addch(out, '\n');
+	strbuf_release(&buf);
+#else
+	struct strbuf buf = STRBUF_INIT;
+	struct statvfs stat;
+
+	strbuf_realpath(&buf, ".", 1);
+	if (statvfs(buf.buf, &stat) < 0) {
+		error_errno(_("could not determine free disk size for '%s'"),
+			    buf.buf);
+		strbuf_release(&buf);
+		return -1;
+	}
+
+	strbuf_addf(out, "Available space on '%s': ", buf.buf);
+	strbuf_humanise_bytes(out, st_mult(stat.f_bsize, stat.f_bavail));
+	strbuf_addf(out, " (mount flags 0x%lx)\n", stat.f_flag);
+	strbuf_release(&buf);
+#endif
+	return 0;
+}
+
 /* printf-style interface, expects `<key>=<value>` argument */
 static int set_config(const char *fmt, ...)
 {
@@ -599,6 +651,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	get_version_info(&buf, 1);
 
 	strbuf_addf(&buf, "Enlistment root: %s\n", the_repository->worktree);
+	get_disk_info(&buf);
 	write_or_die(stdout_fd, buf.buf, buf.len);
 	strvec_pushf(&archiver_args,
 		     "--add-virtual-file=diagnostics.log:%.*s",
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 6802d317258..934b2485d91 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -94,6 +94,7 @@ SQ="'"
 test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	scalar diagnose cloned >out 2>err &&
+	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
 	zip_path=$(cat zip_path) &&
 	test -n "$zip_path" &&

contrib/scalar/scalar.c, contrib/scalar/t/t9099-scalar.sh

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index d302c27e114..0c278681758 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -619,6 +619,60 @@ static int dir_file_stats(struct object_directory *object_dir, void *data)
 	return 0;
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -687,6 +741,11 @@ static int cmd_diagnose(int argc, const char **argv)
 	foreach_alt_odb(dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-virtual-file=objects-local.txt:");
+	loose_objs_stats(&buf, ".git/objects");
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 3dd5650cceb..72023a1ca1d 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -95,6 +95,7 @@ test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	git repack &&
 	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
+	test_commit -C cloned/src loose &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -106,7 +107,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
-	grep "$(pwd)/.git/objects" out
+	grep "$(pwd)/.git/objects" out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
+	grep "^Total: [1-9]" out
 '
 
 test_done

Documentation/git-archive.txt, archive.c, t/t5003-archive-zip.sh

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index 94519aae23..b41cc5bc2e 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -51,7 +51,7 @@ OPTIONS
 --prefix=<prefix>/::
 	Prepend <prefix>/ to paths in the archive.  Can be repeated; its
 	rightmost value is used for all tracked files.  See below which
-	value gets used by `--add-file`.
+	value gets used by `--add-file` and `--add-virtual-file`.
 
 -o <file>::
 --output=<file>::
@@ -63,6 +63,17 @@ OPTIONS
 	concatenating the value of the last `--prefix` option (if any)
 	before this `--add-file` and the basename of <file>.
 
+--add-virtual-file=<path>:<content>::
+	Add the specified contents to the archive.  Can be repeated to add
+	multiple files.  The path of the file in the archive is built
+	by concatenating the value of the last `--prefix` option (if any)
+	before this `--add-virtual-file` and `<path>`.
++
+The `<path>` cannot contain any colon, the file mode is limited to
+a regular file, and the option may be subject to platform-dependent
+command-line limits. For non-trivial cases, write an untracked file
+and use `--add-file` instead.
+
 --worktree-attributes::
 	Look for attributes in .gitattributes files in the working tree
 	as well (see <<ATTRIBUTES>>).
diff --git a/archive.c b/archive.c
index e2121ebefb..d26f4ef945 100644
--- a/archive.c
+++ b/archive.c
@@ -263,6 +263,7 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 struct extra_file_info {
 	char *base;
 	struct stat stat;
+	void *content;
 };
 
 int write_archive_entries(struct archiver_args *args,
@@ -331,19 +332,27 @@ int write_archive_entries(struct archiver_args *args,
 
 		put_be64(fake_oid.hash, i + 1);
 
-		strbuf_reset(&path_in_archive);
-		if (info->base)
-			strbuf_addstr(&path_in_archive, info->base);
-		strbuf_addstr(&path_in_archive, basename(path));
-
-		strbuf_reset(&content);
-		if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
-			err = error_errno(_("cannot read '%s'"), path);
-		else
-			err = write_entry(args, &fake_oid, path_in_archive.buf,
-					  path_in_archive.len,
+		if (!info->content) {
+			strbuf_reset(&path_in_archive);
+			if (info->base)
+				strbuf_addstr(&path_in_archive, info->base);
+			strbuf_addstr(&path_in_archive, basename(path));
+
+			strbuf_reset(&content);
+			if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
+				err = error_errno(_("could not read '%s'"), path);
+			else
+				err = write_entry(args, &fake_oid, path_in_archive.buf,
+						  path_in_archive.len,
+						  canon_mode(info->stat.st_mode),
+						  content.buf, content.len);
+		} else {
+			err = write_entry(args, &fake_oid,
+					  path, strlen(path),
 					  canon_mode(info->stat.st_mode),
-					  content.buf, content.len);
+					  info->content, info->stat.st_size);
+		}
+
 		if (err)
 			break;
 	}
@@ -493,6 +502,7 @@ static void extra_file_info_clear(void *util, const char *str)
 {
 	struct extra_file_info *info = util;
 	free(info->base);
+	free(info->content);
 	free(info);
 }
 
@@ -514,14 +524,40 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	if (!arg)
 		return -1;
 
-	path = prefix_filename(args->prefix, arg);
-	item = string_list_append_nodup(&args->extra_files, path);
-	item->util = info = xmalloc(sizeof(*info));
+	info = xmalloc(sizeof(*info));
 	info->base = xstrdup_or_null(base);
-	if (stat(path, &info->stat))
-		die(_("File not found: %s"), path);
-	if (!S_ISREG(info->stat.st_mode))
-		die(_("Not a regular file: %s"), path);
+
+	if (!strcmp(opt->long_name, "add-file")) {
+		path = prefix_filename(args->prefix, arg);
+		if (stat(path, &info->stat))
+			die(_("File not found: %s"), path);
+		if (!S_ISREG(info->stat.st_mode))
+			die(_("Not a regular file: %s"), path);
+		info->content = NULL; /* read the file later */
+	} else if (!strcmp(opt->long_name, "add-virtual-file")) {
+		const char *colon = strchr(arg, ':');
+		char *p;
+
+		if (!colon)
+			die(_("missing colon: '%s'"), arg);
+
+		p = xstrndup(arg, colon - arg);
+		if (!args->prefix)
+			path = p;
+		else {
+			path = prefix_filename(args->prefix, p);
+			free(p);
+		}
+		memset(&info->stat, 0, sizeof(info->stat));
+		info->stat.st_mode = S_IFREG | 0644;
+		info->content = xstrdup(colon + 1);
+		info->stat.st_size = strlen(info->content);
+	} else {
+		BUG("add_file_cb() called for %s", opt->long_name);
+	}
+	item = string_list_append_nodup(&args->extra_files, path);
+	item->util = info;
+
 	return 0;
 }
 
@@ -554,6 +590,9 @@ static int parse_archive_args(int argc, const char **argv,
 		{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
 		  N_("add untracked file to archive"), 0, add_file_cb,
 		  (intptr_t)&base },
+		{ OPTION_CALLBACK, 0, "add-virtual-file", args,
+		  N_("path:content"), N_("add untracked file to archive"), 0,
+		  add_file_cb, (intptr_t)&base },
 		OPT_STRING('o', "output", &output, N_("file"),
 			N_("write the archive to this file")),
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index d726964307..d6027189e2 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -206,6 +206,18 @@ test_expect_success 'git archive --format=zip --add-file' '
 check_zip with_untracked
 check_added with_untracked untracked untracked
 
+test_expect_success UNZIP 'git archive --format=zip --add-virtual-file' '
+	git archive --format=zip >with_file_with_content.zip \
+		--add-virtual-file=hello:world $EMPTY_TREE &&
+	test_when_finished "rm -rf tmp-unpack" &&
+	mkdir tmp-unpack && (
+		cd tmp-unpack &&
+		"$GIT_UNZIP" ../with_file_with_content.zip &&
+		test_path_is_file hello &&
+		test world = $(cat hello)
+	)
+'
+
 test_expect_success 'git archive --format=zip --add-file twice' '
 	echo untracked >untracked &&
 	git archive --format=zip --prefix=one/ --add-file=untracked \