patcht0060: skip a few relative_path tests on Windows

diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index dfe4747..4deec52 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -190,15 +190,15 @@ test_expect_success SYMLINKS 'real path works on
symlinks' '

 relative_path /a/b/c/	/a/b/		c/
 relative_path /a/b/c/	/a/b		c/
-relative_path /a//b//c/	//a/b//		c/
+relative_path /a//b//c/	//a/b//		c/	POSIX
 relative_path /a/b	/a/b		./
 relative_path /a/b/	/a/b		./
 relative_path /a	/a/b		../
 relative_path /		/a/b/		../../
 relative_path /a/c	/a/b/		../c
 relative_path /a/c	/a/b		../c
-relative_path /a/b	"<empty>"	/a/b
-relative_path /a/b 	"<null>"	/a/b
+relative_path /a/b	"<empty>"	/a/b	POSIX
+relative_path /a/b 	"<null>"	/a/b	POSIX
 relative_path "<empty>"	/a/b		./
 relative_path "<empty>"	"<empty>"	./
 relative_path "<empty>"	"<null>"	./

t/t0060-path-utils.sh, test-path-utils.c

diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index 09a42..7e258 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -12,6 +12,11 @@ norm_path() {
 	"test \"\$(test-path-utils normalize_path_copy '$1')\" = '$2'"
 }
 
+relative_path() {
+	test_expect_success $4 "relative path: $1 $2 => $3" \
+	"test \"\$(test-path-utils relative_path '$1' '$2')\" = '$3'"
+}
+
 # On Windows, we are using MSYS's bash, which mangles the paths.
 # Absolute paths are anchored at the MSYS installation directory,
 # which means that the path / accounts for this many characters:
@@ -183,4 +188,25 @@ test_expect_success SYMLINKS 'real path works on symlinks' '
 	test "$sym" = "$(test-path-utils real_path "$dir2/syml")"
 '
 
+relative_path /a/b/c/	/a/b/		c/
+relative_path /a/b/c/	/a/b		c/
+relative_path /a//b//c/	//a/b//		c/	POSIX
+relative_path /a/b	/a/b		.
+relative_path /a/b/	/a/b		.
+relative_path /a	/a/b		/a	POSIX
+relative_path /		/a/b/		/	POSIX
+relative_path /a/c	/a/b/		/a/c	POSIX
+relative_path /a/c	/a/b		/a/c	POSIX
+relative_path /a/b	"<empty>"	/a/b	POSIX
+relative_path /a/b 	"<null>"	/a/b	POSIX
+relative_path "<empty>"	/a/b		"(empty)"
+relative_path "<empty>"	"<empty>"	"(empty)"
+relative_path "<empty>"	"<null>"	"(empty)"
+relative_path "<null>"	"<empty>"	"(null)"
+relative_path "<null>"	"<null>"	"(null)"
+
+test_expect_failure 'relative path: <null> /a/b => segfault' '
+	test-path-utils relative_path "<null>" "/a/b"
+'
+
 test_done
diff --git a/test-path-utils.c b/test-path-utils.c
index 0092cb..dcc530 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -28,6 +28,19 @@ static int normalize_ceiling_entry(struct string_list_item *item, void *unused)
 	return 1;
 }
 
+static void normalize_argv_string(const char **var, const char *input)
+{
+	if (!strcmp(input, "<null>"))
+		*var = NULL;
+	else if (!strcmp(input, "<empty>"))
+		*var = "";
+	else
+		*var = input;
+
+	if (*var && (**var == '<' || **var == '('))
+		die("Bad value: %s\n", input);
+}
+
 int main(int argc, char **argv)
 {
 	if (argc == 3 && !strcmp(argv[1], "normalize_path_copy")) {
@@ -103,6 +116,18 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
+	if (argc == 4 && !strcmp(argv[1], "relative_path")) {
+		const char *abs, *base, *rel;
+		normalize_argv_string(&abs, argv[2]);
+		normalize_argv_string(&base, argv[3]);
+		rel = relative_path(abs, base);
+		if (!rel)
+			puts("(null)");
+		else
+			puts(strlen(rel) > 0 ? rel : "(empty)");
+		return 0;
+	}
+
 	fprintf(stderr, "%s: unknown function name: %s\n", argv[0],
 		argv[1] ? argv[1] : "(there was none)");
 	return 1;

cache.h, path.c, setup.c, t/t0060-path-utils.sh, test-path-utils.c

diff --git a/cache.h b/cache.h
index dd0fb..2f10c 100644
--- a/cache.h
+++ b/cache.h
@@ -758,7 +758,7 @@ int is_directory(const char *);
 const char *real_path(const char *path);
 const char *real_path_if_valid(const char *path);
 const char *absolute_path(const char *path);
-const char *relative_path(const char *abs, const char *base);
+const char *relative_path(const char *abs, const char *base, struct strbuf *sb);
 int normalize_path_copy(char *dst, const char *src);
 int longest_ancestor_length(const char *path, struct string_list *prefixes);
 char *strip_path_suffix(const char *path, const char *suffix);
diff --git a/path.c b/path.c
index 04ff..8ff16 100644
--- a/path.c
+++ b/path.c
@@ -441,42 +441,104 @@ int adjust_shared_perm(const char *path)
 	return 0;
 }
 
-const char *relative_path(const char *abs, const char *base)
+/*
+ * Give relative path for abs to base.
+ *
+ * The strbuf may or may not be used, so do not assume it contains the
+ * returned path.
+ */
+const char *relative_path(const char *abs, const char *base,
+			  struct strbuf *sb)
 {
-	static char buf[PATH_MAX + 1];
-	int i = 0, j = 0;
-
-	if (!base || !base[0])
+	int abs_off, base_off, i, j;
+	int abs_len, base_len;
+
+	abs_len = abs ? strlen(abs) : 0;
+	base_len = base ? strlen(base) : 0;
+	abs_off = 0;
+	base_off = 0;
+	i = 0;
+	j = 0;
+
+	if (!abs_len)
+		return "./";
+	else if (!base_len)
 		return abs;
-	while (base[i]) {
+
+	while (i < base_len && j < abs_len && base[i] == abs[j]) {
 		if (is_dir_sep(base[i])) {
-			if (!is_dir_sep(abs[j]))
-				return abs;
 			while (is_dir_sep(base[i]))
 				i++;
 			while (is_dir_sep(abs[j]))
 				j++;
-			continue;
-		} else if (abs[j] != base[i]) {
+			base_off = i;
+			abs_off = j;
+		} else {
+			i++;
+			j++;
+		}
+	}
+
+	if (
+	    /* base seems like prefix of abs */
+	    i >= base_len &&
+	    /*
+	     * but "/foo" is not a prefix of "/foobar"
+	     * (i.e. base not end with '/')
+	     */
+	    base_off < base_len) {
+		if (j >= abs_len) {
+			/* abs="/a/b", base="/a/b" */
+			abs_off = abs_len;
+		} else if (is_dir_sep(abs[j])) {
+			/* abs="/a/b/c", base="/a/b" */
+			while (is_dir_sep(abs[j]))
+				j++;
+			abs_off = j;
+		} else {
+			/* abs="/a/bbb/c", base="/a/b" */
+			i = base_off;
+		}
+	} else if (
+		   /* abs is short than base (prefix of base) */
+		   j >= abs_len &&
+		   /* abs not end with '/' */
+		   abs_off < abs_len) {
+		if (is_dir_sep(base[i])) {
+			/* abs="/a/b", base="/a/b/c/" */
+			while (is_dir_sep(base[i]))
+				i++;
+			abs_off = abs_len;
+		}
+	}
+	abs += abs_off;
+	abs_len -= abs_off;
+
+	if (i >= base_len) {
+		if (!abs_len)
+			return "./";
+		else
 			return abs;
+	}
+
+	strbuf_reset(sb);
+	strbuf_grow(sb, abs_len);
+
+	while (i < base_len) {
+		if (is_dir_sep(base[i])) {
+			strbuf_addstr(sb, "../");
+			while (is_dir_sep(base[i]))
+				i++;
+			continue;
 		}
 		i++;
-		j++;
 	}
-	if (
-	    /* "/foo" is a prefix of "/foo" */
-	    abs[j] &&
-	    /* "/foo" is not a prefix of "/foobar" */
-	    !is_dir_sep(base[i-1]) && !is_dir_sep(abs[j])
-	   )
-		return abs;
-	while (is_dir_sep(abs[j]))
-		j++;
-	if (!abs[j])
-		strcpy(buf, ".");
-	else
-		strcpy(buf, abs + j);
-	return buf;
+	if (!is_dir_sep(base[base_len - 1]))
+		strbuf_addstr(sb, "../");
+
+	strbuf_addstr(sb, abs);
+
+	return sb->buf;
 }
 
 /*
diff --git a/setup.c b/setup.c
index 94c1e..0d9ea 100644
--- a/setup.c
+++ b/setup.c
@@ -360,6 +360,7 @@ int is_inside_work_tree(void)
 
 void setup_work_tree(void)
 {
+	struct strbuf sb = STRBUF_INIT;
 	const char *work_tree, *git_dir;
 	static int initialized = 0;
 
@@ -379,8 +380,10 @@ void setup_work_tree(void)
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 		setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 
-	set_git_dir(relative_path(git_dir, work_tree));
+	set_git_dir(relative_path(git_dir, work_tree, &sb));
 	initialized = 1;
+
+	strbuf_release(&sb);
 }
 
 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index 7e258..4deec 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -191,22 +191,19 @@ test_expect_success SYMLINKS 'real path works on symlinks' '
 relative_path /a/b/c/	/a/b/		c/
 relative_path /a/b/c/	/a/b		c/
 relative_path /a//b//c/	//a/b//		c/	POSIX
-relative_path /a/b	/a/b		.
-relative_path /a/b/	/a/b		.
-relative_path /a	/a/b		/a	POSIX
-relative_path /		/a/b/		/	POSIX
-relative_path /a/c	/a/b/		/a/c	POSIX
-relative_path /a/c	/a/b		/a/c	POSIX
+relative_path /a/b	/a/b		./
+relative_path /a/b/	/a/b		./
+relative_path /a	/a/b		../
+relative_path /		/a/b/		../../
+relative_path /a/c	/a/b/		../c
+relative_path /a/c	/a/b		../c
 relative_path /a/b	"<empty>"	/a/b	POSIX
 relative_path /a/b 	"<null>"	/a/b	POSIX
-relative_path "<empty>"	/a/b		"(empty)"
-relative_path "<empty>"	"<empty>"	"(empty)"
-relative_path "<empty>"	"<null>"	"(empty)"
-relative_path "<null>"	"<empty>"	"(null)"
-relative_path "<null>"	"<null>"	"(null)"
-
-test_expect_failure 'relative path: <null> /a/b => segfault' '
-	test-path-utils relative_path "<null>" "/a/b"
-'
+relative_path "<empty>"	/a/b		./
+relative_path "<empty>"	"<empty>"	./
+relative_path "<empty>"	"<null>"	./
+relative_path "<null>"	"<empty>"	./
+relative_path "<null>"	"<null>"	./
+relative_path "<null>"	/a/b		./
 
 test_done
diff --git a/test-path-utils.c b/test-path-utils.c
index dcc530..95ef4 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -117,14 +117,16 @@ int main(int argc, char **argv)
 	}
 
 	if (argc == 4 && !strcmp(argv[1], "relative_path")) {
+		struct strbuf sb = STRBUF_INIT;
 		const char *abs, *base, *rel;
 		normalize_argv_string(&abs, argv[2]);
 		normalize_argv_string(&base, argv[3]);
-		rel = relative_path(abs, base);
+		rel = relative_path(abs, base, &sb);
 		if (!rel)
 			puts("(null)");
 		else
 			puts(strlen(rel) > 0 ? rel : "(empty)");
+		strbuf_release(&sb);
 		return 0;
 	}
 

diff --git a/quote.c b/quote.c
index 91122..64ff3 100644
--- a/quote.c
+++ b/quote.c
@@ -312,75 +312,24 @@ void write_name_quotedpfx(const char *pfx, size_t pfxlen,
 	fputc(terminator, fp);
 }
 
-static const char *path_relative(const char *in, int len,
-				 struct strbuf *sb, const char *prefix,
-				 int prefix_len);
-
 void write_name_quoted_relative(const char *name, size_t len,
 				const char *prefix, size_t prefix_len,
 				FILE *fp, int terminator)
 {
 	struct strbuf sb = STRBUF_INIT;
 
-	name = path_relative(name, len, &sb, prefix, prefix_len);
+	name = relative_path(name, prefix, &sb);
 	write_name_quoted(name, fp, terminator);
 
 	strbuf_release(&sb);
 }
 
-/*
- * Give path as relative to prefix.
- *
- * The strbuf may or may not be used, so do not assume it contains the
- * returned path.
- */
-static const char *path_relative(const char *in, int len,
-				 struct strbuf *sb, const char *prefix,
-				 int prefix_len)
-{
-	int off, i;
-
-	if (len < 0)
-		len = strlen(in);
-	if (prefix_len < 0) {
-		if (prefix)
-			prefix_len = strlen(prefix);
-		else
-			prefix_len = 0;
-	}
-
-	off = 0;
-	i = 0;
-	while (i < prefix_len && i < len && prefix[i] == in[i]) {
-		if (prefix[i] == '/')
-			off = i + 1;
-		i++;
-	}
-	in += off;
-	len -= off;
-
-	if (i >= prefix_len)
-		return in;
-
-	strbuf_reset(sb);
-	strbuf_grow(sb, len);
-
-	while (i < prefix_len) {
-		if (prefix[i] == '/')
-			strbuf_addstr(sb, "../");
-		i++;
-	}
-	strbuf_add(sb, in, len);
-
-	return sb->buf;
-}
-
 /* quote path as relative to the given prefix */
 char *quote_path_relative(const char *in, int len,
 			  struct strbuf *out, const char *prefix)
 {
 	struct strbuf sb = STRBUF_INIT;
-	const char *rel = path_relative(in, len, &sb, prefix, -1);
+	const char *rel = relative_path(in, prefix, &sb);
 	strbuf_reset(out);
 	quote_c_style_counted(rel, strlen(rel), out, NULL, 0);
 	strbuf_release(&sb);

builtin/clean.c, builtin/grep.c, builtin/ls-files.c, quote.c, quote.h, wt-status.c

diff --git a/builtin/clean.c b/builtin/clean.c
index 04e39..f77f95 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -56,7 +56,7 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 	if ((force_flag & REMOVE_DIR_KEEP_NESTED_GIT) &&
 			!resolve_gitlink_ref(path->buf, "HEAD", submodule_head)) {
 		if (!quiet) {
-			quote_path_relative(path->buf, strlen(path->buf), &quoted, prefix);
+			quote_path_relative(path->buf, prefix, &quoted);
 			printf(dry_run ?  _(msg_would_skip_git_dir) : _(msg_skip_git_dir),
 					quoted.buf);
 		}
@@ -70,7 +70,7 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 		/* an empty dir could be removed even if it is unreadble */
 		res = dry_run ? 0 : rmdir(path->buf);
 		if (res) {
-			quote_path_relative(path->buf, strlen(path->buf), &quoted, prefix);
+			quote_path_relative(path->buf, prefix, &quoted);
 			warning(_(msg_warn_remove_failed), quoted.buf);
 			*dir_gone = 0;
 		}
@@ -94,7 +94,7 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 			if (remove_dirs(path, prefix, force_flag, dry_run, quiet, &gone))
 				ret = 1;
 			if (gone) {
-				quote_path_relative(path->buf, strlen(path->buf), &quoted, prefix);
+				quote_path_relative(path->buf, prefix, &quoted);
 				string_list_append(&dels, quoted.buf);
 			} else
 				*dir_gone = 0;
@@ -102,10 +102,10 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 		} else {
 			res = dry_run ? 0 : unlink(path->buf);
 			if (!res) {
-				quote_path_relative(path->buf, strlen(path->buf), &quoted, prefix);
+				quote_path_relative(path->buf, prefix, &quoted);
 				string_list_append(&dels, quoted.buf);
 			} else {
-				quote_path_relative(path->buf, strlen(path->buf), &quoted, prefix);
+				quote_path_relative(path->buf, prefix, &quoted);
 				warning(_(msg_warn_remove_failed), quoted.buf);
 				*dir_gone = 0;
 				ret = 1;
@@ -127,7 +127,7 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 		if (!res)
 			*dir_gone = 1;
 		else {
-			quote_path_relative(path->buf, strlen(path->buf), &quoted, prefix);
+			quote_path_relative(path->buf, prefix, &quoted);
 			warning(_(msg_warn_remove_failed), quoted.buf);
 			*dir_gone = 0;
 			ret = 1;
@@ -262,7 +262,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 				if (remove_dirs(&directory, prefix, rm_flags, dry_run, quiet, &gone))
 					errors++;
 				if (gone && !quiet) {
-					qname = quote_path_relative(directory.buf, directory.len, &buf, prefix);
+					qname = quote_path_relative(directory.buf, prefix, &buf);
 					printf(dry_run ? _(msg_would_remove) : _(msg_remove), qname);
 				}
 			}
@@ -272,11 +272,11 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 				continue;
 			res = dry_run ? 0 : unlink(ent->name);
 			if (res) {
-				qname = quote_path_relative(ent->name, -1, &buf, prefix);
+				qname = quote_path_relative(ent->name, prefix, &buf);
 				warning(_(msg_warn_remove_failed), qname);
 				errors++;
 			} else if (!quiet) {
-				qname = quote_path_relative(ent->name, -1, &buf, prefix);
+				qname = quote_path_relative(ent->name, prefix, &buf);
 				printf(dry_run ? _(msg_would_remove) : _(msg_remove), qname);
 			}
 		}
diff --git a/builtin/grep.c b/builtin/grep.c
index 159e65..a419c 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -286,8 +286,7 @@ static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 	struct strbuf pathbuf = STRBUF_INIT;
 
 	if (opt->relative && opt->prefix_length) {
-		quote_path_relative(filename + tree_name_len, -1, &pathbuf,
-				    opt->prefix);
+		quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
 		strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 	} else {
 		strbuf_addstr(&pathbuf, filename);
@@ -318,7 +317,7 @@ static int grep_file(struct grep_opt *opt, const char *filename)
 	struct strbuf buf = STRBUF_INIT;
 
 	if (opt->relative && opt->prefix_length)
-		quote_path_relative(filename, -1, &buf, opt->prefix);
+		quote_path_relative(filename, opt->prefix, &buf);
 	else
 		strbuf_addstr(&buf, filename);
 
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 3a410c..16d4f 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -391,7 +391,7 @@ int report_path_error(const char *ps_matched, const char **pathspec, const char
 		if (found_dup)
 			continue;
 
-		name = quote_path_relative(pathspec[num], -1, &sb, prefix);
+		name = quote_path_relative(pathspec[num], prefix, &sb);
 		error("pathspec '%s' did not match any file(s) known to git.",
 		      name);
 		errors++;
diff --git a/quote.c b/quote.c
index 64ff3..ebb8 100644
--- a/quote.c
+++ b/quote.c
@@ -325,8 +325,8 @@ void write_name_quoted_relative(const char *name, size_t len,
 }
 
 /* quote path as relative to the given prefix */
-char *quote_path_relative(const char *in, int len,
-			  struct strbuf *out, const char *prefix)
+char *quote_path_relative(const char *in, const char *prefix,
+			  struct strbuf *out)
 {
 	struct strbuf sb = STRBUF_INIT;
 	const char *rel = relative_path(in, prefix, &sb);
@@ -334,9 +334,6 @@ char *quote_path_relative(const char *in, int len,
 	quote_c_style_counted(rel, strlen(rel), out, NULL, 0);
 	strbuf_release(&sb);
 
-	if (!out->len)
-		strbuf_addstr(out, "./");
-
 	return out->buf;
 }
 
diff --git a/quote.h b/quote.h
index 13315..5610159 100644
--- a/quote.h
+++ b/quote.h
@@ -65,8 +65,8 @@ extern void write_name_quoted_relative(const char *name, size_t len,
 		FILE *fp, int terminator);
 
 /* quote path as relative to the given prefix */
-extern char *quote_path_relative(const char *in, int len,
-			  struct strbuf *out, const char *prefix);
+extern char *quote_path_relative(const char *in, const char *prefix,
+			  struct strbuf *out);
 
 /* quoting as a string literal for other languages */
 extern void perl_quote_print(FILE *stream, const char *src);
diff --git a/wt-status.c b/wt-status.c
index 438a40..85580 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -243,7 +243,7 @@ static void wt_status_print_unmerged_data(struct wt_status *s,
 	struct strbuf onebuf = STRBUF_INIT;
 	const char *one, *how = _("bug");
 
-	one = quote_path(it->string, -1, &onebuf, s->prefix);
+	one = quote_path(it->string, s->prefix, &onebuf);
 	status_printf(s, color(WT_STATUS_HEADER, s), "\t");
 	switch (d->stagemask) {
 	case 1: how = _("both deleted:"); break;
@@ -297,8 +297,8 @@ static void wt_status_print_change_data(struct wt_status *s,
 		    change_type);
 	}
 
-	one = quote_path(one_name, -1, &onebuf, s->prefix);
-	two = quote_path(two_name, -1, &twobuf, s->prefix);
+	one = quote_path(one_name, s->prefix, &onebuf);
+	two = quote_path(two_name, s->prefix, &twobuf);
 
 	status_printf(s, color(WT_STATUS_HEADER, s), "\t");
 	switch (status) {
@@ -706,8 +706,7 @@ static void wt_status_print_other(struct wt_status *s,
 		struct string_list_item *it;
 		const char *path;
 		it = &(l->items[i]);
-		path = quote_path(it->string, strlen(it->string),
-				  &buf, s->prefix);
+		path = quote_path(it->string, s->prefix, &buf);
 		if (column_active(s->colopts)) {
 			string_list_append(&output, path);
 			continue;
@@ -1291,7 +1290,7 @@ static void wt_shortstatus_unmerged(struct string_list_item *it,
 	} else {
 		struct strbuf onebuf = STRBUF_INIT;
 		const char *one;
-		one = quote_path(it->string, -1, &onebuf, s->prefix);
+		one = quote_path(it->string, s->prefix, &onebuf);
 		printf(" %s\n", one);
 		strbuf_release(&onebuf);
 	}
@@ -1319,7 +1318,7 @@ static void wt_shortstatus_status(struct string_list_item *it,
 		struct strbuf onebuf = STRBUF_INIT;
 		const char *one;
 		if (d->head_path) {
-			one = quote_path(d->head_path, -1, &onebuf, s->prefix);
+			one = quote_path(d->head_path, s->prefix, &onebuf);
 			if (*one != '"' && strchr(one, ' ') != NULL) {
 				putchar('"');
 				strbuf_addch(&onebuf, '"');
@@ -1328,7 +1327,7 @@ static void wt_shortstatus_status(struct string_list_item *it,
 			printf("%s -> ", one);
 			strbuf_release(&onebuf);
 		}
-		one = quote_path(it->string, -1, &onebuf, s->prefix);
+		one = quote_path(it->string, s->prefix, &onebuf);
 		if (*one != '"' && strchr(one, ' ') != NULL) {
 			putchar('"');
 			strbuf_addch(&onebuf, '"');
@@ -1347,7 +1346,7 @@ static void wt_shortstatus_other(struct string_list_item *it,
 	} else {
 		struct strbuf onebuf = STRBUF_INIT;
 		const char *one;
-		one = quote_path(it->string, -1, &onebuf, s->prefix);
+		one = quote_path(it->string, s->prefix, &onebuf);
 		color_fprintf(s->fp, color(WT_STATUS_UNTRACKED, s), "%s", sign);
 		printf(" %s\n", one);
 		strbuf_release(&onebuf);

builtin/ls-files.c, quote.c, quote.h

diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 16d4f..df83f9 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -46,10 +46,12 @@ static const char *tag_modified = "";
 static const char *tag_skip_worktree = "";
 static const char *tag_resolve_undo = "";
 
-static void write_name(const char* name, size_t len)
+static void write_name(const char *name)
 {
-	write_name_quoted_relative(name, len, prefix, prefix_len, stdout,
-			line_terminator);
+
+	/* turn off prefix, if run with "--full-name" */
+	write_name_quoted_relative(name, prefix_len ? prefix : NULL,
+				   stdout, line_terminator);
 }
 
 static void show_dir_entry(const char *tag, struct dir_entry *ent)
@@ -63,7 +65,7 @@ static void show_dir_entry(const char *tag, struct dir_entry *ent)
 		return;
 
 	fputs(tag, stdout);
-	write_name(ent->name, ent->len);
+	write_name(ent->name);
 }
 
 static void show_other_files(struct dir_struct *dir)
@@ -163,7 +165,7 @@ static void show_ce_entry(const char *tag, struct cache_entry *ce)
 		       find_unique_abbrev(ce->sha1,abbrev),
 		       ce_stage(ce));
 	}
-	write_name(ce->name, ce_namelen(ce));
+	write_name(ce->name);
 	if (debug_mode) {
 		struct stat_data *sd = &ce->ce_stat_data;
 
@@ -198,7 +200,7 @@ static void show_ru_info(void)
 			printf("%s%06o %s %d\t", tag_resolve_undo, ui->mode[i],
 			       find_unique_abbrev(ui->sha1[i], abbrev),
 			       i + 1);
-			write_name(path, len);
+			write_name(path);
 		}
 	}
 }
diff --git a/quote.c b/quote.c
index ebb8..5c880 100644
--- a/quote.c
+++ b/quote.c
@@ -312,8 +312,7 @@ void write_name_quotedpfx(const char *pfx, size_t pfxlen,
 	fputc(terminator, fp);
 }
 
-void write_name_quoted_relative(const char *name, size_t len,
-				const char *prefix, size_t prefix_len,
+void write_name_quoted_relative(const char *name, const char *prefix,
 				FILE *fp, int terminator)
 {
 	struct strbuf sb = STRBUF_INIT;
diff --git a/quote.h b/quote.h
index 5610159..ed110 100644
--- a/quote.h
+++ b/quote.h
@@ -60,8 +60,7 @@ extern void quote_two_c_style(struct strbuf *, const char *, const char *, int);
 extern void write_name_quoted(const char *name, FILE *, int terminator);
 extern void write_name_quotedpfx(const char *pfx, size_t pfxlen,
                                  const char *name, FILE *, int terminator);
-extern void write_name_quoted_relative(const char *name, size_t len,
-		const char *prefix, size_t prefix_len,
+extern void write_name_quoted_relative(const char *name, const char *prefix,
 		FILE *fp, int terminator);
 
 /* quote path as relative to the given prefix */

diff --git a/builtin/clean.c b/builtin/clean.c
index f77f95..77ec1 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -15,6 +15,7 @@
 #include "quote.h"
 
 static int force = -1; /* unset */
+static struct string_list del_list = STRING_LIST_INIT_DUP;
 
 static const char *const builtin_clean_usage[] = {
 	N_("git clean [-d] [-f] [-n] [-q] [-e <pattern>] [-x | -X] [--] <paths>..."),
@@ -148,12 +149,13 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 	int dry_run = 0, remove_directories = 0, quiet = 0, ignored = 0;
 	int ignored_only = 0, config_set = 0, errors = 0, gone = 1;
 	int rm_flags = REMOVE_DIR_KEEP_NESTED_GIT;
-	struct strbuf directory = STRBUF_INIT;
+	struct strbuf abs_path = STRBUF_INIT;
 	struct dir_struct dir;
 	static const char **pathspec;
 	struct strbuf buf = STRBUF_INIT;
 	struct string_list exclude_list = STRING_LIST_INIT_NODUP;
 	struct exclude_list *el;
+	struct string_list_item *item;
 	const char *qname;
 	char *seen = NULL;
 	struct option options[] = {
@@ -223,6 +225,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		int matches = 0;
 		struct cache_entry *ce;
 		struct stat st;
+		const char *rel;
 
 		/*
 		 * Remove the '/' at the end that directory
@@ -242,13 +245,8 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 				continue; /* Yup, this one exists unmerged */
 		}
 
-		/*
-		 * we might have removed this as part of earlier
-		 * recursive directory removal, so lstat() here could
-		 * fail with ENOENT.
-		 */
 		if (lstat(ent->name, &st))
-			continue;
+			die_errno("Cannot lstat '%s'", ent->name);
 
 		if (pathspec) {
 			memset(seen, 0, argc > 0 ? argc : 1);
@@ -257,33 +255,61 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		}
 
 		if (S_ISDIR(st.st_mode)) {
-			strbuf_addstr(&directory, ent->name);
 			if (remove_directories || (matches == MATCHED_EXACTLY)) {
-				if (remove_dirs(&directory, prefix, rm_flags, dry_run, quiet, &gone))
-					errors++;
-				if (gone && !quiet) {
-					qname = quote_path_relative(directory.buf, prefix, &buf);
-					printf(dry_run ? _(msg_would_remove) : _(msg_remove), qname);
-				}
+				rel = relative_path(ent->name, prefix, &buf);
+				string_list_append(&del_list, rel);
 			}
-			strbuf_reset(&directory);
 		} else {
 			if (pathspec && !matches)
 				continue;
-			res = dry_run ? 0 : unlink(ent->name);
+			rel = relative_path(ent->name, prefix, &buf);
+			string_list_append(&del_list, rel);
+		}
+	}
+
+	/* TODO: do interactive git-clean here, which will modify del_list */
+
+	for_each_string_list_item(item, &del_list) {
+		struct stat st;
+
+		if (prefix)
+			strbuf_addstr(&abs_path, prefix);
+
+		strbuf_addstr(&abs_path, item->string);
+
+		/*
+		 * we might have removed this as part of earlier
+		 * recursive directory removal, so lstat() here could
+		 * fail with ENOENT.
+		 */
+		if (lstat(abs_path.buf, &st))
+			continue;
+
+		if (S_ISDIR(st.st_mode)) {
+			if (remove_dirs(&abs_path, prefix, rm_flags, dry_run, quiet, &gone))
+				errors++;
+			if (gone && !quiet) {
+				qname = quote_path_relative(item->string, NULL, &buf);
+				printf(dry_run ? _(msg_would_remove) : _(msg_remove), qname);
+			}
+		} else {
+			res = dry_run ? 0 : unlink(abs_path.buf);
 			if (res) {
-				qname = quote_path_relative(ent->name, prefix, &buf);
+				qname = quote_path_relative(item->string, NULL, &buf);
 				warning(_(msg_warn_remove_failed), qname);
 				errors++;
 			} else if (!quiet) {
-				qname = quote_path_relative(ent->name, prefix, &buf);
+				qname = quote_path_relative(item->string, NULL, &buf);
 				printf(dry_run ? _(msg_would_remove) : _(msg_remove), qname);
 			}
 		}
+		strbuf_reset(&abs_path);
 	}
 	free(seen);
 
-	strbuf_release(&directory);
+	strbuf_release(&abs_path);
+	strbuf_release(&buf);
+	string_list_clear(&del_list, 0);
 	string_list_clear(&exclude_list, 0);
 	return (errors != 0);
 }

Documentation/git-clean.txt, builtin/clean.c

diff --git a/Documentation/git-clean.txt b/Documentation/git-clean.txt
index bdc3a..186e34 100644
--- a/Documentation/git-clean.txt
+++ b/Documentation/git-clean.txt
@@ -8,7 +8,7 @@ git-clean - Remove untracked files from the working tree
 SYNOPSIS
 --------
 [verse]
-'git clean' [-d] [-f] [-n] [-q] [-e <pattern>] [-x | -X] [--] <path>...
+'git clean' [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] <path>...
 
 DESCRIPTION
 -----------
@@ -34,7 +34,13 @@ OPTIONS
 -f::
 --force::
 	If the Git configuration variable clean.requireForce is not set
-	to false, 'git clean' will refuse to run unless given -f or -n.
+	to false, 'git clean' will refuse to run unless given -f, -n or
+	-i.
+
+-i::
+--interactive::
+	Show what would be done and the user must confirm before actually
+	cleaning.
 
 -n::
 --dry-run::
diff --git a/builtin/clean.c b/builtin/clean.c
index 77ec1..698fb 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -15,10 +15,11 @@
 #include "quote.h"
 
 static int force = -1; /* unset */
+static int interactive;
 static struct string_list del_list = STRING_LIST_INIT_DUP;
 
 static const char *const builtin_clean_usage[] = {
-	N_("git clean [-d] [-f] [-n] [-q] [-e <pattern>] [-x | -X] [--] <paths>..."),
+	N_("git clean [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] <paths>..."),
 	NULL
 };
 
@@ -143,6 +144,50 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 	return ret;
 }
 
+static void interactive_main_loop(void)
+{
+	struct strbuf confirm = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct string_list_item *item;
+	const char *qname;
+
+	while (del_list.nr) {
+		putchar('\n');
+		for_each_string_list_item(item, &del_list) {
+			qname = quote_path_relative(item->string, NULL, &buf);
+			printf(_(msg_would_remove), qname);
+		}
+		putchar('\n');
+
+		printf(_("Remove [y/n]? "));
+		if (strbuf_getline(&confirm, stdin, '\n') != EOF) {
+			strbuf_trim(&confirm);
+		} else {
+			/* Ctrl-D is the same as "quit" */
+			string_list_clear(&del_list, 0);
+			putchar('\n');
+			printf_ln("Bye.");
+			break;
+		}
+
+		if (confirm.len) {
+			if (!strncasecmp(confirm.buf, "yes", confirm.len)) {
+				break;
+			} else if (!strncasecmp(confirm.buf, "no", confirm.len) ||
+				   !strncasecmp(confirm.buf, "quit", confirm.len)) {
+				string_list_clear(&del_list, 0);
+				printf_ln("Bye.");
+				break;
+			} else {
+				continue;
+			}
+		}
+	}
+
+	strbuf_release(&buf);
+	strbuf_release(&confirm);
+}
+
 int cmd_clean(int argc, const char **argv, const char *prefix)
 {
 	int i, res;
@@ -162,6 +207,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		OPT__QUIET(&quiet, N_("do not print names of files removed")),
 		OPT__DRY_RUN(&dry_run, N_("dry run")),
 		OPT__FORCE(&force, N_("force")),
+		OPT_BOOL('i', "interactive", &interactive, N_("interactive cleaning")),
 		OPT_BOOLEAN('d', NULL, &remove_directories,
 				N_("remove whole directories")),
 		{ OPTION_CALLBACK, 'e', "exclude", &exclude_list, N_("pattern"),
@@ -188,12 +234,12 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 	if (ignored && ignored_only)
 		die(_("-x and -X cannot be used together"));
 
-	if (!dry_run && !force) {
+	if (!interactive && !dry_run && !force) {
 		if (config_set)
-			die(_("clean.requireForce set to true and neither -n nor -f given; "
+			die(_("clean.requireForce set to true and neither -i, -n nor -f given; "
 				  "refusing to clean"));
 		else
-			die(_("clean.requireForce defaults to true and neither -n nor -f given; "
+			die(_("clean.requireForce defaults to true and neither -i, -n nor -f given; "
 				  "refusing to clean"));
 	}
 
@@ -267,7 +313,8 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	/* TODO: do interactive git-clean here, which will modify del_list */
+	if (interactive && del_list.nr > 0)
+		interactive_main_loop();
 
 	for_each_string_list_item(item, &del_list) {
 		struct stat st;

Documentation/config.txt, builtin/clean.c

diff --git a/Documentation/config.txt b/Documentation/config.txt
index e203..c415f 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -959,6 +959,10 @@ column.branch::
 	Specify whether to output branch listing in `git branch` in columns.
 	See `column.ui` for details.
 
+column.clean::
+	Specify the layout when list items in `git clean -i`, which always
+	shows files and directories in columns. See `column.ui` for details.
+
 column.status::
 	Specify whether to output untracked files in `git status` in columns.
 	See `column.ui` for details.
diff --git a/builtin/clean.c b/builtin/clean.c
index 698fb..75cc6 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -13,10 +13,12 @@
 #include "refs.h"
 #include "string-list.h"
 #include "quote.h"
+#include "column.h"
 
 static int force = -1; /* unset */
 static int interactive;
 static struct string_list del_list = STRING_LIST_INIT_DUP;
+static unsigned int colopts;
 
 static const char *const builtin_clean_usage[] = {
 	N_("git clean [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] <paths>..."),
@@ -31,8 +33,13 @@ static const char *msg_warn_remove_failed = N_("failed to remove %s");
 
 static int git_clean_config(const char *var, const char *value, void *cb)
 {
-	if (!strcmp(var, "clean.requireforce"))
+	if (!prefixcmp(var, "column."))
+		return git_column_config(var, value, "clean", &colopts);
+
+	if (!strcmp(var, "clean.requireforce")) {
 		force = !git_config_bool(var, value);
+		return 0;
+	}
 	return git_default_config(var, value, cb);
 }
 
@@ -144,21 +151,46 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 	return ret;
 }
 
-static void interactive_main_loop(void)
+static void pretty_print_dels(void)
 {
-	struct strbuf confirm = STRBUF_INIT;
-	struct strbuf buf = STRBUF_INIT;
+	struct string_list list = STRING_LIST_INIT_DUP;
 	struct string_list_item *item;
+	struct strbuf buf = STRBUF_INIT;
 	const char *qname;
+	struct column_options copts;
+
+	for_each_string_list_item(item, &del_list) {
+		qname = quote_path_relative(item->string, NULL, &buf);
+		string_list_append(&list, qname);
+	}
+
+	/*
+	 * always enable column display, we only consult column.*
+	 * about layout strategy and stuff
+	 */
+	colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
+	memset(&copts, 0, sizeof(copts));
+	copts.indent = "  ";
+	copts.padding = 2;
+	print_columns(&list, colopts, &copts);
+	putchar('\n');
+	strbuf_release(&buf);
+	string_list_clear(&list, 0);
+}
+
+static void interactive_main_loop(void)
+{
+	struct strbuf confirm = STRBUF_INIT;
 
 	while (del_list.nr) {
 		putchar('\n');
-		for_each_string_list_item(item, &del_list) {
-			qname = quote_path_relative(item->string, NULL, &buf);
-			printf(_(msg_would_remove), qname);
-		}
+		printf_ln(Q_("Would remove the following item:",
+			     "Would remove the following items:",
+			     del_list.nr));
 		putchar('\n');
 
+		pretty_print_dels();
+
 		printf(_("Remove [y/n]? "));
 		if (strbuf_getline(&confirm, stdin, '\n') != EOF) {
 			strbuf_trim(&confirm);
@@ -184,7 +216,6 @@ static void interactive_main_loop(void)
 		}
 	}
 
-	strbuf_release(&buf);
 	strbuf_release(&confirm);
 }
 

Documentation/config.txt, builtin/clean.c

diff --git a/Documentation/config.txt b/Documentation/config.txt
index c415f..1b31f 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -879,16 +879,17 @@ The values of these variables may be specified as in color.branch.<slot>.
 
 color.interactive::
 	When set to `always`, always use colors for interactive prompts
-	and displays (such as those used by "git-add --interactive").
-	When false (or `never`), never.  When set to `true` or `auto`, use
-	colors only when the output is to the terminal. Defaults to false.
+	and displays (such as those used by "git-add --interactive" and
+	"git-clean --interactive"). When false (or `never`), never.
+	When set to `true` or `auto`, use colors only when the output is
+	to the terminal. Defaults to false.
 
 color.interactive.<slot>::
-	Use customized color for 'git add --interactive'
-	output. `<slot>` may be `prompt`, `header`, `help` or `error`, for
-	four distinct types of normal output from interactive
-	commands.  The values of these variables may be specified as
-	in color.branch.<slot>.
+	Use customized color for 'git add --interactive' and 'git clean
+	--interactive' output. `<slot>` may be `prompt`, `header`, `help`
+	or `error`, for four distinct types of normal output from
+	interactive commands.  The values of these variables may be
+	specified as in color.branch.<slot>.
 
 color.pager::
 	A boolean to enable/disable colored output when the pager is in
diff --git a/builtin/clean.c b/builtin/clean.c
index 75cc6..dfa99b 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -14,6 +14,7 @@
 #include "string-list.h"
 #include "quote.h"
 #include "column.h"
+#include "color.h"
 
 static int force = -1; /* unset */
 static int interactive;
@@ -31,16 +32,82 @@ static const char *msg_skip_git_dir = N_("Skipping repository %s\n");
 static const char *msg_would_skip_git_dir = N_("Would skip repository %s\n");
 static const char *msg_warn_remove_failed = N_("failed to remove %s");
 
+static int clean_use_color = -1;
+static char clean_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RESET,
+	GIT_COLOR_NORMAL,	/* PLAIN */
+	GIT_COLOR_BOLD_BLUE,	/* PROMPT */
+	GIT_COLOR_BOLD,		/* HEADER */
+	GIT_COLOR_BOLD_RED,	/* HELP */
+	GIT_COLOR_BOLD_RED,	/* ERROR */
+};
+enum color_clean {
+	CLEAN_COLOR_RESET = 0,
+	CLEAN_COLOR_PLAIN = 1,
+	CLEAN_COLOR_PROMPT = 2,
+	CLEAN_COLOR_HEADER = 3,
+	CLEAN_COLOR_HELP = 4,
+	CLEAN_COLOR_ERROR = 5,
+};
+
+static int parse_clean_color_slot(const char *var)
+{
+	if (!strcasecmp(var, "reset"))
+		return CLEAN_COLOR_RESET;
+	if (!strcasecmp(var, "plain"))
+		return CLEAN_COLOR_PLAIN;
+	if (!strcasecmp(var, "prompt"))
+		return CLEAN_COLOR_PROMPT;
+	if (!strcasecmp(var, "header"))
+		return CLEAN_COLOR_HEADER;
+	if (!strcasecmp(var, "help"))
+		return CLEAN_COLOR_HELP;
+	if (!strcasecmp(var, "error"))
+		return CLEAN_COLOR_ERROR;
+	return -1;
+}
+
 static int git_clean_config(const char *var, const char *value, void *cb)
 {
 	if (!prefixcmp(var, "column."))
 		return git_column_config(var, value, "clean", &colopts);
 
+	/* honors the color.interactive* config variables which also
+	   applied in git-add--interactive and git-stash */
+	if (!strcmp(var, "color.interactive")) {
+		clean_use_color = git_config_colorbool(var, value);
+		return 0;
+	}
+	if (!prefixcmp(var, "color.interactive.")) {
+		int slot = parse_clean_color_slot(var +
+						  strlen("color.interactive."));
+		if (slot < 0)
+			return 0;
+		if (!value)
+			return config_error_nonbool(var);
+		color_parse(value, var, clean_colors[slot]);
+		return 0;
+	}
+
 	if (!strcmp(var, "clean.requireforce")) {
 		force = !git_config_bool(var, value);
 		return 0;
 	}
-	return git_default_config(var, value, cb);
+
+	/* inspect the color.ui config variable and others */
+	return git_color_default_config(var, value, cb);
+}
+
+static const char *clean_get_color(enum color_clean ix)
+{
+	if (want_color(clean_use_color))
+		return clean_colors[ix];
+	return "";
+}
+
+static void clean_print_color(enum color_clean ix)
+{
+	printf("%s", clean_get_color(ix));
 }
 
 static int exclude_cb(const struct option *opt, const char *arg, int unset)
@@ -184,14 +251,18 @@ static void interactive_main_loop(void)
 
 	while (del_list.nr) {
 		putchar('\n');
+		clean_print_color(CLEAN_COLOR_HEADER);
 		printf_ln(Q_("Would remove the following item:",
 			     "Would remove the following items:",
 			     del_list.nr));
+		clean_print_color(CLEAN_COLOR_RESET);
 		putchar('\n');
 
 		pretty_print_dels();
 
+		clean_print_color(CLEAN_COLOR_PROMPT);
 		printf(_("Remove [y/n]? "));
+		clean_print_color(CLEAN_COLOR_RESET);
 		if (strbuf_getline(&confirm, stdin, '\n') != EOF) {
 			strbuf_trim(&confirm);
 		} else {

diff --git a/builtin/clean.c b/builtin/clean.c
index dfa99b..df887 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -50,6 +50,36 @@ enum color_clean {
 	CLEAN_COLOR_ERROR = 5,
 };
 
+#define MENU_OPTS_SINGLETON		01
+#define MENU_OPTS_IMMEDIATE		02
+#define MENU_OPTS_LIST_ONLY		04
+
+struct menu_opts {
+	const char *header;
+	const char *prompt;
+	int flags;
+};
+
+#define MENU_RETURN_NO_LOOP		10
+
+struct menu_item {
+	char hotkey;
+	const char *title;
+	int selected;
+	int (*fn)();
+};
+
+enum menu_stuff_type {
+	MENU_STUFF_TYPE_STRING_LIST = 1,
+	MENU_STUFF_TYPE_MENU_ITEM
+};
+
+struct menu_stuff {
+	enum menu_stuff_type type;
+	int nr;
+	void *stuff;
+};
+
 static int parse_clean_color_slot(const char *var)
 {
 	if (!strcasecmp(var, "reset"))
@@ -240,54 +270,422 @@ static void pretty_print_dels(void)
 	copts.indent = "  ";
 	copts.padding = 2;
 	print_columns(&list, colopts, &copts);
-	putchar('\n');
 	strbuf_release(&buf);
 	string_list_clear(&list, 0);
 }
 
-static void interactive_main_loop(void)
+static void pretty_print_menus(struct string_list *menu_list)
+{
+	unsigned int local_colopts = 0;
+	struct column_options copts;
+
+	local_colopts = COL_ENABLED | COL_ROW;
+	memset(&copts, 0, sizeof(copts));
+	copts.indent = "  ";
+	copts.padding = 2;
+	print_columns(menu_list, local_colopts, &copts);
+}
+
+static void prompt_help_cmd(int singleton)
+{
+	clean_print_color(CLEAN_COLOR_HELP);
+	printf_ln(singleton ?
+		  _("Prompt help:\n"
+		    "1          - select a numbered item\n"
+		    "foo        - select item based on unique prefix\n"
+		    "           - (empty) select nothing") :
+		  _("Prompt help:\n"
+		    "1          - select a single item\n"
+		    "3-5        - select a range of items\n"
+		    "2-3,6-9    - select multiple ranges\n"
+		    "foo        - select item based on unique prefix\n"
+		    "-...       - unselect specified items\n"
+		    "*          - choose all items\n"
+		    "           - (empty) finish selecting"));
+	clean_print_color(CLEAN_COLOR_RESET);
+}
+
+/*
+ * display menu stuff with number prefix and hotkey highlight
+ */
+static void print_highlight_menu_stuff(struct menu_stuff *stuff, int **chosen)
+{
+	struct string_list menu_list = STRING_LIST_INIT_DUP;
+	struct strbuf menu = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct menu_item *menu_item;
+	struct string_list_item *string_list_item;
+	int i;
+
+	switch (stuff->type) {
+	default:
+		die("Bad type of menu_staff when print menu");
+	case MENU_STUFF_TYPE_MENU_ITEM:
+		menu_item = (struct menu_item *)stuff->stuff;
+		for (i = 0; i < stuff->nr; i++, menu_item++) {
+			const char *p;
+			int highlighted = 0;
+
+			p = menu_item->title;
+			if ((*chosen)[i] < 0)
+				(*chosen)[i] = menu_item->selected ? 1 : 0;
+			strbuf_addf(&menu, "%s%2d: ", (*chosen)[i] ? "*" : " ", i+1);
+			for (; *p; p++) {
+				if (!highlighted && *p == menu_item->hotkey) {
+					strbuf_addstr(&menu, clean_get_color(CLEAN_COLOR_PROMPT));
+					strbuf_addch(&menu, *p);
+					strbuf_addstr(&menu, clean_get_color(CLEAN_COLOR_RESET));
+					highlighted = 1;
+				} else {
+					strbuf_addch(&menu, *p);
+				}
+			}
+			string_list_append(&menu_list, menu.buf);
+			strbuf_reset(&menu);
+		}
+		break;
+	case MENU_STUFF_TYPE_STRING_LIST:
+		i = 0;
+		for_each_string_list_item(string_list_item, (struct string_list *)stuff->stuff) {
+			if ((*chosen)[i] < 0)
+				(*chosen)[i] = 0;
+			strbuf_addf(&menu, "%s%2d: %s",
+				    (*chosen)[i] ? "*" : " ", i+1, string_list_item->string);
+			string_list_append(&menu_list, menu.buf);
+			strbuf_reset(&menu);
+			i++;
+		}
+		break;
+	}
+
+	pretty_print_menus(&menu_list);
+
+	strbuf_release(&menu);
+	strbuf_release(&buf);
+	string_list_clear(&menu_list, 0);
+}
+
+/*
+ * Parse user input, and return choice(s) for menu (menu_stuff).
+ *
+ * Input
+ *     (for single choice)
+ *         1          - select a numbered item
+ *         foo        - select item based on menu title
+ *                    - (empty) select nothing
+ *
+ *     (for multiple choice)
+ *         1          - select a single item
+ *         3-5        - select a range of items
+ *         2-3,6-9    - select multiple ranges
+ *         foo        - select item based on menu title
+ *         -...       - unselect specified items
+ *         *          - choose all items
+ *                    - (empty) finish selecting
+ *
+ * The parse result will be saved in array **chosen, and
+ * return number of total selections.
+ */
+static int parse_choice(struct menu_stuff *menu_stuff,
+			int is_single,
+			struct strbuf input,
+			int **chosen)
+{
+	struct strbuf **choice_list, **ptr;
+	struct menu_item *menu_item;
+	struct string_list_item *string_list_item;
+	int nr = 0;
+	int i;
+
+	if (is_single) {
+		choice_list = strbuf_split_max(&input, '\n', 0);
+	} else {
+		char *p = input.buf;
+		do {
+			if (*p == ',')
+				*p = ' ';
+		} while (*p++);
+		choice_list = strbuf_split_max(&input, ' ', 0);
+	}
+
+	for (ptr = choice_list; *ptr; ptr++) {
+		char *p;
+		int choose = 1;
+		int bottom = 0, top = 0;
+		int is_range, is_number;
+
+		strbuf_trim(*ptr);
+		if (!(*ptr)->len)
+			continue;
+
+		/* Input that begins with '-'; unchoose */
+		if (*(*ptr)->buf == '-') {
+			choose = 0;
+			strbuf_remove((*ptr), 0, 1);
+		}
+
+		is_range = 0;
+		is_number = 1;
+		for (p = (*ptr)->buf; *p; p++) {
+			if ('-' == *p) {
+				if (!is_range) {
+					is_range = 1;
+					is_number = 0;
+				} else {
+					is_number = 0;
+					is_range = 0;
+					break;
+				}
+			} else if (!isdigit(*p)) {
+				is_number = 0;
+				is_range = 0;
+				break;
+			}
+		}
+
+		if (is_number) {
+			bottom = atoi((*ptr)->buf);
+			top = bottom;
+		} else if (is_range) {
+			bottom = atoi((*ptr)->buf);
+			/* a range can be specified like 5-7 or 5- */
+			if (!*(strchr((*ptr)->buf, '-') + 1))
+				top = menu_stuff->nr;
+			else
+				top = atoi(strchr((*ptr)->buf, '-') + 1);
+		} else if (!strcmp((*ptr)->buf, "*")) {
+			bottom = 1;
+			top = menu_stuff->nr;
+		} else {
+			switch (menu_stuff->type) {
+			default:
+				die("Bad type of menu_stuff when parse choice");
+			case MENU_STUFF_TYPE_MENU_ITEM:
+				menu_item = (struct menu_item *)menu_stuff->stuff;
+				for (i = 0; i < menu_stuff->nr; i++, menu_item++) {
+					if (((*ptr)->len == 1 &&
+					     *(*ptr)->buf == menu_item->hotkey) ||
+					    !strcasecmp((*ptr)->buf, menu_item->title)) {
+						bottom = i + 1;
+						top = bottom;
+						break;
+					}
+				}
+				break;
+			case MENU_STUFF_TYPE_STRING_LIST:
+				string_list_item = ((struct string_list *)menu_stuff->stuff)->items;
+				for (i = 0; i < menu_stuff->nr; i++, string_list_item++) {
+					if (!strcasecmp((*ptr)->buf, string_list_item->string)) {
+						bottom = i + 1;
+						top = bottom;
+						break;
+					}
+				}
+				break;
+			}
+		}
+
+		if (top <= 0 || bottom <= 0 || top > menu_stuff->nr || bottom > top ||
+		    (is_single && bottom != top)) {
+			clean_print_color(CLEAN_COLOR_ERROR);
+			printf_ln(_("Huh (%s)?"), (*ptr)->buf);
+			clean_print_color(CLEAN_COLOR_RESET);
+			continue;
+		}
+
+		for (i = bottom; i <= top; i++)
+			(*chosen)[i-1] = choose;
+	}
+
+	strbuf_list_free(choice_list);
+
+	for (i = 0; i < menu_stuff->nr; i++)
+		nr += (*chosen)[i];
+	return nr;
+}
+
+/*
+ * Implement a git-add-interactive compatible UI, which is borrowed
+ * from git-add--interactive.perl.
+ *
+ * Return value:
+ *
+ *   - Return an array of integers
+ *   - , and it is up to you to free the allocated memory.
+ *   - The array ends with EOF.
+ *   - If user pressed CTRL-D (i.e. EOF), no selection returned.
+ */
+static int *list_and_choose(struct menu_opts *opts, struct menu_stuff *stuff)
+{
+	struct strbuf choice = STRBUF_INIT;
+	int *chosen, *result;
+	int nr = 0;
+	int eof = 0;
+	int i;
+
+	chosen = xmalloc(sizeof(int) * stuff->nr);
+	/* set chosen as uninitialized */
+	for (i = 0; i < stuff->nr; i++)
+		chosen[i] = -1;
+
+	for (;;) {
+		if (opts->header) {
+			printf_ln("%s%s%s",
+				  clean_get_color(CLEAN_COLOR_HEADER),
+				  _(opts->header),
+				  clean_get_color(CLEAN_COLOR_RESET));
+		}
+
+		/* chosen will be initialized by print_highlight_menu_stuff */
+		print_highlight_menu_stuff(stuff, &chosen);
+
+		if (opts->flags & MENU_OPTS_LIST_ONLY)
+			break;
+
+		if (opts->prompt) {
+			printf("%s%s%s%s",
+			       clean_get_color(CLEAN_COLOR_PROMPT),
+			       _(opts->prompt),
+			       opts->flags & MENU_OPTS_SINGLETON ? "> " : ">> ",
+			       clean_get_color(CLEAN_COLOR_RESET));
+		}
+
+		if (strbuf_getline(&choice, stdin, '\n') != EOF) {
+			strbuf_trim(&choice);
+		} else {
+			eof = 1;
+			break;
+		}
+
+		/* help for prompt */
+		if (!strcmp(choice.buf, "?")) {
+			prompt_help_cmd(opts->flags & MENU_OPTS_SINGLETON);
+			continue;
+		}
+
+		/* for a multiple-choice menu, press ENTER (empty) will return back */
+		if (!(opts->flags & MENU_OPTS_SINGLETON) && !choice.len)
+			break;
+
+		nr = parse_choice(stuff,
+				  opts->flags & MENU_OPTS_SINGLETON,
+				  choice,
+				  &chosen);
+
+		if (opts->flags & MENU_OPTS_SINGLETON) {
+			if (nr)
+				break;
+		} else if (opts->flags & MENU_OPTS_IMMEDIATE) {
+			break;
+		}
+	}
+
+	if (eof) {
+		result = xmalloc(sizeof(int));
+		*result = EOF;
+	} else {
+		int j = 0;
+
+		/*
+		 * recalculate nr, if return back from menu directly with
+		 * default selections.
+		 */
+		if (!nr) {
+			for (i = 0; i < stuff->nr; i++)
+				nr += chosen[i];
+		}
+
+		result = xmalloc(sizeof(int) * (nr + 1));
+		memset(result, 0, sizeof(int) * (nr + 1));
+		for (i = 0; i < stuff->nr && j < nr; i++) {
+			if (chosen[i])
+				result[j++] = i;
+		}
+		result[j] = EOF;
+	}
+
+	free(chosen);
+	strbuf_release(&choice);
+	return result;
+}
+
+static int clean_cmd(void)
 {
-	struct strbuf confirm = STRBUF_INIT;
+	return MENU_RETURN_NO_LOOP;
+}
+
+static int quit_cmd(void)
+{
+	string_list_clear(&del_list, 0);
+	printf_ln(_("Bye."));
+	return MENU_RETURN_NO_LOOP;
+}
+
+static int help_cmd(void)
+{
+	clean_print_color(CLEAN_COLOR_HELP);
+	printf_ln(_(
+		    "clean               - start cleaning\n"
+		    "quit                - stop cleaning\n"
+		    "help                - this screen\n"
+		    "?                   - help for prompt selection"
+		   ));
+	clean_print_color(CLEAN_COLOR_RESET);
+	return 0;
+}
 
+static void interactive_main_loop(void)
+{
 	while (del_list.nr) {
-		putchar('\n');
+		struct menu_opts menu_opts;
+		struct menu_stuff menu_stuff;
+		struct menu_item menus[] = {
+			{'c', "clean",			0, clean_cmd},
+			{'q', "quit",			0, quit_cmd},
+			{'h', "help",			0, help_cmd},
+		};
+		int *chosen;
+
+		menu_opts.header = N_("*** Commands ***");
+		menu_opts.prompt = N_("What now");
+		menu_opts.flags = MENU_OPTS_SINGLETON;
+
+		menu_stuff.type = MENU_STUFF_TYPE_MENU_ITEM;
+		menu_stuff.stuff = menus;
+		menu_stuff.nr = sizeof(menus) / sizeof(struct menu_item);
+
 		clean_print_color(CLEAN_COLOR_HEADER);
 		printf_ln(Q_("Would remove the following item:",
 			     "Would remove the following items:",
 			     del_list.nr));
 		clean_print_color(CLEAN_COLOR_RESET);
-		putchar('\n');
 
 		pretty_print_dels();
 
-		clean_print_color(CLEAN_COLOR_PROMPT);
-		printf(_("Remove [y/n]? "));
-		clean_print_color(CLEAN_COLOR_RESET);
-		if (strbuf_getline(&confirm, stdin, '\n') != EOF) {
-			strbuf_trim(&confirm);
-		} else {
-			/* Ctrl-D is the same as "quit" */
-			string_list_clear(&del_list, 0);
-			putchar('\n');
-			printf_ln("Bye.");
-			break;
-		}
-
-		if (confirm.len) {
-			if (!strncasecmp(confirm.buf, "yes", confirm.len)) {
-				break;
-			} else if (!strncasecmp(confirm.buf, "no", confirm.len) ||
-				   !strncasecmp(confirm.buf, "quit", confirm.len)) {
-				string_list_clear(&del_list, 0);
-				printf_ln("Bye.");
-				break;
-			} else {
+		chosen = list_and_choose(&menu_opts, &menu_stuff);
+
+		if (*chosen != EOF) {
+			int ret;
+			ret = menus[*chosen].fn();
+			if (ret != MENU_RETURN_NO_LOOP) {
+				free(chosen);
+				chosen = NULL;
+				if (!del_list.nr) {
+					clean_print_color(CLEAN_COLOR_ERROR);
+					printf_ln(_("No more files to clean, exiting."));
+					clean_print_color(CLEAN_COLOR_RESET);
+					break;
+				}
 				continue;
 			}
+		} else {
+			quit_cmd();
 		}
-	}
 
-	strbuf_release(&confirm);
+		free(chosen);
+		chosen = NULL;
+		break;
+	}
 }
 
 int cmd_clean(int argc, const char **argv, const char *prefix)

diff --git a/builtin/clean.c b/builtin/clean.c
index df887..36369 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -614,6 +614,72 @@ static int clean_cmd(void)
 	return MENU_RETURN_NO_LOOP;
 }
 
+static int filter_by_patterns_cmd(void)
+{
+	struct dir_struct dir;
+	struct strbuf confirm = STRBUF_INIT;
+	struct strbuf **ignore_list;
+	struct string_list_item *item;
+	struct exclude_list *el;
+	int changed = -1, i;
+
+	for (;;) {
+		if (!del_list.nr)
+			break;
+
+		if (changed)
+			pretty_print_dels();
+
+		clean_print_color(CLEAN_COLOR_PROMPT);
+		printf(_("Input ignore patterns>> "));
+		clean_print_color(CLEAN_COLOR_RESET);
+		if (strbuf_getline(&confirm, stdin, '\n') != EOF)
+			strbuf_trim(&confirm);
+		else
+			putchar('\n');
+
+		/* quit filter_by_pattern mode if press ENTER or Ctrl-D */
+		if (!confirm.len)
+			break;
+
+		memset(&dir, 0, sizeof(dir));
+		el = add_exclude_list(&dir, EXC_CMDL, "manual exclude");
+		ignore_list = strbuf_split_max(&confirm, ' ', 0);
+
+		for (i = 0; ignore_list[i]; i++) {
+			strbuf_trim(ignore_list[i]);
+			if (!ignore_list[i]->len)
+				continue;
+
+			add_exclude(ignore_list[i]->buf, "", 0, el, -(i+1));
+		}
+
+		changed = 0;
+		for_each_string_list_item(item, &del_list) {
+			int dtype = DT_UNKNOWN;
+
+			if (is_excluded(&dir, item->string, &dtype)) {
+				*item->string = '\0';
+				changed++;
+			}
+		}
+
+		if (changed) {
+			string_list_remove_empty_items(&del_list, 0);
+		} else {
+			clean_print_color(CLEAN_COLOR_ERROR);
+			printf_ln(_("WARNING: Cannot find items matched by: %s"), confirm.buf);
+			clean_print_color(CLEAN_COLOR_RESET);
+		}
+
+		strbuf_list_free(ignore_list);
+		clear_directory(&dir);
+	}
+
+	strbuf_release(&confirm);
+	return 0;
+}
+
 static int quit_cmd(void)
 {
 	string_list_clear(&del_list, 0);
@@ -626,6 +692,7 @@ static int help_cmd(void)
 	clean_print_color(CLEAN_COLOR_HELP);
 	printf_ln(_(
 		    "clean               - start cleaning\n"
+		    "filter by pattern   - exclude items from deletion\n"
 		    "quit                - stop cleaning\n"
 		    "help                - this screen\n"
 		    "?                   - help for prompt selection"
@@ -641,6 +708,7 @@ static void interactive_main_loop(void)
 		struct menu_stuff menu_stuff;
 		struct menu_item menus[] = {
 			{'c', "clean",			0, clean_cmd},
+			{'f', "filter by pattern",	0, filter_by_patterns_cmd},
 			{'q', "quit",			0, quit_cmd},
 			{'h', "help",			0, help_cmd},
 		};

diff --git a/builtin/clean.c b/builtin/clean.c
index 36369..643a5e 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -680,6 +680,43 @@ static int filter_by_patterns_cmd(void)
 	return 0;
 }
 
+static int select_by_numbers_cmd(void)
+{
+	struct menu_opts menu_opts;
+	struct menu_stuff menu_stuff;
+	struct string_list_item *items;
+	int *chosen;
+	int i, j;
+
+	menu_opts.header = NULL;
+	menu_opts.prompt = N_("Select items to delete");
+	menu_opts.flags = 0;
+
+	menu_stuff.type = MENU_STUFF_TYPE_STRING_LIST;
+	menu_stuff.stuff = &del_list;
+	menu_stuff.nr = del_list.nr;
+
+	chosen = list_and_choose(&menu_opts, &menu_stuff);
+	items = del_list.items;
+	for (i = 0, j = 0; i < del_list.nr; i++) {
+		if (i < chosen[j]) {
+			*(items[i].string) = '\0';
+		} else if (i == chosen[j]) {
+			/* delete selected item */
+			j++;
+			continue;
+		} else {
+			/* end of chosen (chosen[j] == EOF), won't delete */
+			*(items[i].string) = '\0';
+		}
+	}
+
+	string_list_remove_empty_items(&del_list, 0);
+
+	free(chosen);
+	return 0;
+}
+
 static int quit_cmd(void)
 {
 	string_list_clear(&del_list, 0);
@@ -693,6 +730,7 @@ static int help_cmd(void)
 	printf_ln(_(
 		    "clean               - start cleaning\n"
 		    "filter by pattern   - exclude items from deletion\n"
+		    "select by numbers   - select items to be deleted by numbers\n"
 		    "quit                - stop cleaning\n"
 		    "help                - this screen\n"
 		    "?                   - help for prompt selection"
@@ -709,6 +747,7 @@ static void interactive_main_loop(void)
 		struct menu_item menus[] = {
 			{'c', "clean",			0, clean_cmd},
 			{'f', "filter by pattern",	0, filter_by_patterns_cmd},
+			{'s', "select by numbers",	0, select_by_numbers_cmd},
 			{'q', "quit",			0, quit_cmd},
 			{'h', "help",			0, help_cmd},
 		};

diff --git a/builtin/clean.c b/builtin/clean.c
index 643a5e..bf03a 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -717,6 +717,40 @@ static int select_by_numbers_cmd(void)
 	return 0;
 }
 
+static int ask_each_cmd(void)
+{
+	struct strbuf confirm = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct string_list_item *item;
+	const char *qname;
+	int changed = 0, eof = 0;
+
+	for_each_string_list_item(item, &del_list) {
+		/* Ctrl-D should stop removing files */
+		if (!eof) {
+			qname = quote_path_relative(item->string, NULL, &buf);
+			printf(_("remove %s? "), qname);
+			if (strbuf_getline(&confirm, stdin, '\n') != EOF) {
+				strbuf_trim(&confirm);
+			} else {
+				putchar('\n');
+				eof = 1;
+			}
+		}
+		if (!confirm.len || strncasecmp(confirm.buf, "yes", confirm.len)) {
+			*item->string = '\0';
+			changed++;
+		}
+	}
+
+	if (changed)
+		string_list_remove_empty_items(&del_list, 0);
+
+	strbuf_release(&buf);
+	strbuf_release(&confirm);
+	return MENU_RETURN_NO_LOOP;
+}
+
 static int quit_cmd(void)
 {
 	string_list_clear(&del_list, 0);
@@ -731,6 +765,7 @@ static int help_cmd(void)
 		    "clean               - start cleaning\n"
 		    "filter by pattern   - exclude items from deletion\n"
 		    "select by numbers   - select items to be deleted by numbers\n"
+		    "ask each            - confirm each deletion (like \"rm -i\")\n"
 		    "quit                - stop cleaning\n"
 		    "help                - this screen\n"
 		    "?                   - help for prompt selection"
@@ -748,6 +783,7 @@ static void interactive_main_loop(void)
 			{'c', "clean",			0, clean_cmd},
 			{'f', "filter by pattern",	0, filter_by_patterns_cmd},
 			{'s', "select by numbers",	0, select_by_numbers_cmd},
+			{'a', "ask each",		0, ask_each_cmd},
 			{'q', "quit",			0, quit_cmd},
 			{'h', "help",			0, help_cmd},
 		};

diff --git a/Documentation/git-clean.txt b/Documentation/git-clean.txt
index 186e34..5bf76 100644
--- a/Documentation/git-clean.txt
+++ b/Documentation/git-clean.txt
@@ -39,8 +39,8 @@ OPTIONS
 
 -i::
 --interactive::
-	Show what would be done and the user must confirm before actually
-	cleaning.
+	Show what would be done and clean files interactively. See
+	``Interactive mode'' for details.
 
 -n::
 --dry-run::
@@ -69,6 +69,67 @@ OPTIONS
 	Remove only files ignored by Git.  This may be useful to rebuild
 	everything from scratch, but keep manually created files.
 
+Interactive mode
+----------------
+When the command enters the interactive mode, it shows the
+files and directories to be cleaned, and goes into its
+interactive command loop.
+
+The command loop shows the list of subcommands available, and
+gives a prompt "What now> ".  In general, when the prompt ends
+with a single '>', you can pick only one of the choices given
+and type return, like this:
+
+------------
+    *** Commands ***
+        1: clean                2: filter by pattern    3: select by numbers
+        4: ask each             5: quit                 6: help
+    What now> 1
+------------
+
+You also could say `c` or `clean` above as long as the choice is unique.
+
+The main command loop has 6 subcommands.
+
+clean::
+
+   Start cleaning files and directories, and then quit.
+
+filter by pattern::
+
+   This shows the files and directories to be deleted and issues an
+   "Input ignore patterns>>" prompt. You can input space-seperated
+   patterns to exclude files and directories from deletion.
+   E.g. "*.c *.h" will excludes files end with ".c" and ".h" from
+   deletion. When you are satisfied with the filtered result, press
+   ENTER (empty) back to the main menu.
+
+select by numbers::
+
+   This shows the files and directories to be deleted and issues an
+   "Select items to delete>>" prompt. When the prompt ends with double
+   '>>' like this, you can make more than one selection, concatenated
+   with whitespace or comma.  Also you can say ranges.  E.g. "2-5 7,9"
+   to choose 2,3,4,5,7,9 from the list.  If the second number in a
+   range is omitted, all remaining patches are taken.  E.g. "7-" to
+   choose 7,8,9 from the list.  You can say '*' to choose everything.
+   Also when you are satisfied with the filtered result, press ENTER
+   (empty) back to the main menu.
+
+ask each::
+
+  This will start to clean, and you must confirm one by one in order
+  to delete items. Please note that this action is not as efficient
+  as the above two actions.
+
+quit::
+
+  This lets you quit without do cleaning.
+
+help::
+
+  Show brief usage of interactive git-clean.
+
 SEE ALSO
 --------
 linkgit:gitignore[5]

diff --git a/t/t7301-clean-interactive.sh b/t/t7301-clean-interactive.sh
new file mode 100755
index 00000..4e605
--- /dev/null
+++ b/t/t7301-clean-interactive.sh
@@ -0,0 +1,439 @@
+#!/bin/sh
+
+test_description='git clean -i basic tests'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+
+	mkdir -p src &&
+	touch src/part1.c Makefile &&
+	echo build >.gitignore &&
+	echo \*.o >>.gitignore &&
+	git add . &&
+	git commit -m setup &&
+	touch src/part2.c README &&
+	git add .
+
+'
+
+test_expect_success 'git clean -i (clean)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	echo c | git clean -i &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test ! -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -i (quit)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	echo q | git clean -i &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -i (Ctrl+D)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	echo "\04" | git clean -i &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (filter all)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo f; echo "*"; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (filter patterns)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo f; echo "part3.* *.out"; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test ! -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test ! -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (filter patterns 2)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo f; echo "* !*.out"; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - all)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo "*"; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test ! -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test ! -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - none)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - number)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo 3; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - number 2)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo 2 3; echo 5; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test ! -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - number 3)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo 3,4 5; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - range)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo 1,3-4; echo 2; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test ! -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test ! -f docs/manual.txt &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (select - range 2)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo 4- 1; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test ! -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (inverse select)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo s; echo "*"; echo -5- 1 -2; echo; echo c) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (ask)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo a; echo Y; echo y; echo no; echo yes; echo bad; echo) | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test ! -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id (ask - Ctrl+D)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(echo a; echo Y; echo no; echo yes; echo "\04") | \
+	git clean -id &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id with prefix and path (filter)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(cd build/ && \
+	 (echo f; echo "docs"; echo "*.h"; echo ; echo c) | \
+	 git clean -id ..) &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id with prefix and path (select by name)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(cd build/ && \
+	 (echo s; echo "../docs/"; echo "../src/part3.c"; \
+	  echo "../src/part4.c";  echo; echo c) | \
+	 git clean -id ..) &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test ! -f docs/manual.txt &&
+	test ! -f src/part3.c &&
+	test -f src/part3.h &&
+	test ! -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_expect_success 'git clean -id with prefix and path (ask)' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c src/part3.h src/part4.c src/part4.h \
+	docs/manual.txt obj.o build/lib.so &&
+	(cd build/ && \
+	 (echo a; echo Y; echo y; echo no; echo yes; echo bad; echo) | \
+	 git clean -id ..) &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test ! -f docs/manual.txt &&
+	test -f src/part3.c &&
+	test ! -f src/part3.h &&
+	test -f src/part4.c &&
+	test -f src/part4.h &&
+	test -f obj.o &&
+	test -f build/lib.so
+
+'
+
+test_done

t/t0060-path-utils.sh, test-path-utils.c

diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index 4deec..dac84 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -7,14 +7,39 @@ test_description='Test various path utilities'
 
 . ./test-lib.sh
 
+mingw_path() {
+	case $2 in
+	NO_MINGW)
+		echo "$1"
+		;;
+	*)
+		test-path-utils mingw_path "$1"
+		;;
+	esac
+}
+
+get_prereq_flag() {
+	case $1 in
+	POSIX)
+		echo $1
+		;;
+	*)
+		;;
+	esac
+}
+
 norm_path() {
-	test_expect_success $3 "normalize path: $1 => $2" \
-	"test \"\$(test-path-utils normalize_path_copy '$1')\" = '$2'"
+	expected=$(mingw_path "$2" "$3")
+	prereq=$(get_prereq_flag $3)
+	test_expect_success $prereq "normalize path: $1 => $2" \
+	"test \"\$(test-path-utils normalize_path_copy '$1')\" = '$expected'"
 }
 
 relative_path() {
-	test_expect_success $4 "relative path: $1 $2 => $3" \
-	"test \"\$(test-path-utils relative_path '$1' '$2')\" = '$3'"
+	expected=$(mingw_path "$3" "$4")
+	prereq=$(get_prereq_flag $4)
+	test_expect_success $prereq "relative path: $1 $2 => $3" \
+	"test \"\$(test-path-utils relative_path '$1' '$2')\" = '$expected'"
 }
 
 # On Windows, we are using MSYS's bash, which mangles the paths.
@@ -39,8 +64,8 @@ ancestor() {
 	 test \"\$actual\" = '$expected'"
 }
 
-# Absolute path tests must be skipped on Windows because due to path mangling
-# the test program never sees a POSIX-style absolute path
+# Some absolute path tests should be skipped on Windows due to path mangling
+# on POSIX-style absolute paths
 case $(uname -s) in
 *MINGW*)
 	;;
@@ -73,10 +98,10 @@ norm_path d1/s1//../s2/../../d2 d2
 norm_path d1/.../d2 d1/.../d2
 norm_path d1/..././../d2 d1/d2
 
-norm_path / / POSIX
-norm_path // / POSIX
-norm_path /// / POSIX
-norm_path /. / POSIX
+norm_path / /
+norm_path // / NO_MINGW
+norm_path /// / NO_MINGW
+norm_path /. /
 norm_path /./ / POSIX
 norm_path /./.. ++failed++ POSIX
 norm_path /../. ++failed++ POSIX
@@ -84,19 +109,19 @@ norm_path /./../.// ++failed++ POSIX
 norm_path /dir/.. / POSIX
 norm_path /dir/sub/../.. / POSIX
 norm_path /dir/sub/../../.. ++failed++ POSIX
-norm_path /dir /dir POSIX
-norm_path /dir// /dir/ POSIX
-norm_path /./dir /dir POSIX
-norm_path /dir/. /dir/ POSIX
-norm_path /dir///./ /dir/ POSIX
-norm_path /dir//sub/.. /dir/ POSIX
-norm_path /dir/sub/../ /dir/ POSIX
+norm_path /dir /dir
+norm_path /dir// /dir/
+norm_path /./dir /dir
+norm_path /dir/. /dir/
+norm_path /dir///./ /dir/
+norm_path /dir//sub/.. /dir/
+norm_path /dir/sub/../ /dir/
 norm_path //dir/sub/../. /dir/ POSIX
-norm_path /dir/s1/../s2/ /dir/s2/ POSIX
-norm_path /d1/s1///s2/..//../s3/ /d1/s3/ POSIX
-norm_path /d1/s1//../s2/../../d2 /d2 POSIX
-norm_path /d1/.../d2 /d1/.../d2 POSIX
-norm_path /d1/..././../d2 /d1/d2 POSIX
+norm_path /dir/s1/../s2/ /dir/s2/
+norm_path /d1/s1///s2/..//../s3/ /d1/s3/
+norm_path /d1/s1//../s2/../../d2 /d2
+norm_path /d1/.../d2 /d1/.../d2
+norm_path /d1/..././../d2 /d1/d2
 
 ancestor / / -1
 ancestor /foo / 0
@@ -197,8 +222,8 @@ relative_path /a	/a/b		../
 relative_path /		/a/b/		../../
 relative_path /a/c	/a/b/		../c
 relative_path /a/c	/a/b		../c
-relative_path /a/b	"<empty>"	/a/b	POSIX
-relative_path /a/b 	"<null>"	/a/b	POSIX
+relative_path /a/b	"<empty>"	/a/b
+relative_path /a/b 	"<null>"	/a/b
 relative_path "<empty>"	/a/b		./
 relative_path "<empty>"	"<empty>"	./
 relative_path "<empty>"	"<null>"	./
diff --git a/test-path-utils.c b/test-path-utils.c
index 95ef4..699ef 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -116,6 +116,11 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
+	if (argc == 3 && !strcmp(argv[1], "mingw_path")) {
+		puts(argv[2]);
+		return 0;
+	}
+
 	if (argc == 4 && !strcmp(argv[1], "relative_path")) {
 		struct strbuf sb = STRBUF_INIT;
 		const char *abs, *base, *rel;

t/t0060-path-utils.sh, test-path-utils.c

diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index 4deec..d5f35 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -8,13 +8,15 @@ test_description='Test various path utilities'
 . ./test-lib.sh

 norm_path() {
+	expected=$(test-path-utils mingw_path "$2")
 	test_expect_success $3 "normalize path: $1 => $2" \
-	"test \"\$(test-path-utils normalize_path_copy '$1')\" = '$2'"
+	"test \"\$(test-path-utils normalize_path_copy '$1')\" = '$expected'"
 }

 relative_path() {
+	expected=$(test-path-utils mingw_path "$3")
 	test_expect_success $4 "relative path: $1 $2 => $3" \
-	"test \"\$(test-path-utils relative_path '$1' '$2')\" = '$3'"
+	"test \"\$(test-path-utils relative_path '$1' '$2')\" = '$expected'"
 }

 # On Windows, we are using MSYS's bash, which mangles the paths.
@@ -39,8 +41,8 @@ ancestor() {
 	 test \"\$actual\" = '$expected'"
 }

-# Absolute path tests must be skipped on Windows because due to path mangling
-# the test program never sees a POSIX-style absolute path
+# Some absolute path tests should be skipped on Windows due to path mangling
+# on POSIX-style absolute paths
 case $(uname -s) in
 *MINGW*)
 	;;
@@ -73,10 +75,10 @@ norm_path d1/s1//../s2/../../d2 d2
 norm_path d1/.../d2 d1/.../d2
 norm_path d1/..././../d2 d1/d2

-norm_path / / POSIX
+norm_path / /
 norm_path // / POSIX
 norm_path /// / POSIX
-norm_path /. / POSIX
+norm_path /. /
 norm_path /./ / POSIX
 norm_path /./.. ++failed++ POSIX
 norm_path /../. ++failed++ POSIX
@@ -84,19 +86,19 @@ norm_path /./../.// ++failed++ POSIX
 norm_path /dir/.. / POSIX
 norm_path /dir/sub/../.. / POSIX
 norm_path /dir/sub/../../.. ++failed++ POSIX
-norm_path /dir /dir POSIX
-norm_path /dir// /dir/ POSIX
-norm_path /./dir /dir POSIX
-norm_path /dir/. /dir/ POSIX
-norm_path /dir///./ /dir/ POSIX
-norm_path /dir//sub/.. /dir/ POSIX
-norm_path /dir/sub/../ /dir/ POSIX
+norm_path /dir /dir
+norm_path /dir// /dir/
+norm_path /./dir /dir
+norm_path /dir/. /dir/
+norm_path /dir///./ /dir/
+norm_path /dir//sub/.. /dir/
+norm_path /dir/sub/../ /dir/
 norm_path //dir/sub/../. /dir/ POSIX
-norm_path /dir/s1/../s2/ /dir/s2/ POSIX
-norm_path /d1/s1///s2/..//../s3/ /d1/s3/ POSIX
-norm_path /d1/s1//../s2/../../d2 /d2 POSIX
-norm_path /d1/.../d2 /d1/.../d2 POSIX
-norm_path /d1/..././../d2 /d1/d2 POSIX
+norm_path /dir/s1/../s2/ /dir/s2/
+norm_path /d1/s1///s2/..//../s3/ /d1/s3/
+norm_path /d1/s1//../s2/../../d2 /d2
+norm_path /d1/.../d2 /d1/.../d2
+norm_path /d1/..././../d2 /d1/d2

 ancestor / / -1
 ancestor /foo / 0
@@ -197,8 +199,8 @@ relative_path /a	/a/b		../
 relative_path /		/a/b/		../../
 relative_path /a/c	/a/b/		../c
 relative_path /a/c	/a/b		../c
-relative_path /a/b	"<empty>"	/a/b	POSIX
-relative_path /a/b 	"<null>"	/a/b	POSIX
+relative_path /a/b	"<empty>"	/a/b
+relative_path /a/b 	"<null>"	/a/b
 relative_path "<empty>"	/a/b		./
 relative_path "<empty>"	"<empty>"	./
 relative_path "<empty>"	"<null>"	./
diff --git a/test-path-utils.c b/test-path-utils.c
index 95ef4..699ef 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -116,6 +116,11 @@ int main(int argc, char **argv)
 		return 0;
 	}

+	if (argc == 3 && !strcmp(argv[1], "mingw_path")) {
+		puts(argv[2]);
+		return 0;
+	}
+
 	if (argc == 4 && !strcmp(argv[1], "relative_path")) {
 		struct strbuf sb = STRBUF_INIT;
 		const char *abs, *base, *rel;