git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v4 4/4] builtin/stash: provide a way to import stashes from a ref

From
brian m. carlson <sandals@crustytoothpaste.net>
Date
Apr 7, 2022, 21:53 UTC
Message-ID
<20220407215352.3491567-5-sandals@crustytoothpaste.net>
In-Reply-To
<20220407215352.3491567-1-sandals@crustytoothpaste.net>

Now that we have a way to export stashes to a ref, let's provide a way to import them from such a ref back to the stash. This works much the way the export code does, except that we strip off the first parent chain commit and then store each resulting commit back to the stash.

We don't clear the stash first and instead add the specified stashes to the top of the stash. This is because users may want to export just a few stashes, such as to share a small amount of work in progress with a colleague, and it would be undesirable for the receiving user to lose all of their data. For users who do want to replace the stash, it's easy to do to: simply run "git stash clear" first.

We specifically rely on the fact that we'll produce identical stash commits on both sides in our tests. This provides a cheap, straightforward check for our tests and also makes it easy for users to see if they already have the same data in both repositories.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
 Documentation/git-stash.txt |   7 +++
 builtin/stash.c             | 105 ++++++++++++++++++++++++++++++++++++
 t/t3903-stash.sh            |  63 ++++++++++++++++++++++
 3 files changed, 175 insertions(+)
diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
index 162110314e..28eb9cab0c 100644
--- a/Documentation/git-stash.txt
+++ b/Documentation/git-stash.txt
@@ -21,6 +21,7 @@ SYNOPSIS
 'git stash' create [<message>]
 'git stash' store [-m|--message <message>] [-q|--quiet] <commit>
 'git stash' export ( --print | --to-ref <ref> ) [<stash>...]
+'git stash' import <commit>
 
 DESCRIPTION
 -----------
@@ -158,6 +159,12 @@ export ( --print | --to-ref <ref> ) [<stash>...]::
 	a chain of commits which can be transferred using the normal fetch and
 	push mechanisms, then imported using the `import` subcommand.
 
+import <commit>::
+
+	Import the specified stashes from the specified commit, which must have been
+	created by `export`, and add them to the list of stashes.  To replace the
+	existing stashes, use `clear` first.
+
 OPTIONS
 -------
 -a::
diff --git a/builtin/stash.c b/builtin/stash.c
index 07b0897eda..06fa74c0c2 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -34,6 +34,7 @@ static const char * const git_stash_usage[] = {
 	N_("git stash save [-p|--patch] [-S|--staged] [-k|--[no-]keep-index] [-q|--quiet]\n"
 	   "          [-u|--include-untracked] [-a|--all] [<message>]"),
 	N_("git stash export (--print | --to-ref <ref>) [<stash>...]"),
+	N_("git stash import <commit>"),
 	NULL
 };
 
@@ -95,6 +96,10 @@ static const char * const git_stash_export_usage[] = {
 	NULL
 };
 
+static const char * const git_stash_import_usage[] = {
+	N_("git stash import <commit>"),
+	NULL
+};
 
 static const char ref_stash[] = "refs/stash";
 static struct strbuf stash_index_path = STRBUF_INIT;
@@ -104,6 +109,7 @@ static struct strbuf stash_index_path = STRBUF_INIT;
  * b_commit is set to the base commit
  * i_commit is set to the commit containing the index tree
  * u_commit is set to the commit containing the untracked files tree
+ * c_commit is set to the first parent (chain commit) when importing and is otherwise unset
  * w_tree is set to the working tree
  * b_tree is set to the base tree
  * i_tree is set to the index tree
@@ -114,6 +120,7 @@ struct stash_info {
 	struct object_id b_commit;
 	struct object_id i_commit;
 	struct object_id u_commit;
+	struct object_id c_commit;
 	struct object_id w_tree;
 	struct object_id b_tree;
 	struct object_id i_tree;
@@ -1827,6 +1834,102 @@ static int write_commit_with_parents(struct object_id *out, const struct object_
 	return ret;
 }
 
+static int do_import_stash(const char *rev)
+{
+	struct object_id chain;
+	struct oid_array items = OID_ARRAY_INIT;
+	int res = 0;
+	int i;
+	const char *buffer = NULL;
+	struct commit *this = NULL;
+	char *msg = NULL;
+
+	if (get_oid(rev, &chain))
+		return error(_("not a valid revision: %s"), rev);
+
+	/*
+	 * Walk the commit history, finding each stash entry, and load data into
+	 * the array.
+	 */
+	for (i = 0;; i++) {
+		struct object_id tree, oid;
+		char revision[GIT_MAX_HEXSZ + 1];
+
+		oid_to_hex_r(revision, &chain);
+
+		if (get_oidf(&tree, "%s:", revision) ||
+		    !oideq(&tree, the_hash_algo->empty_tree)) {
+			return error(_("%s is not a valid exported stash commit"), revision);
+		}
+		if (get_oidf(&chain, "%s^1", revision) ||
+		    get_oidf(&oid, "%s^2", revision))
+			break;
+		oid_array_append(&items, &oid);
+	}
+
+	/*
+	 * Now, walk each entry, adding it to the stash as a normal stash
+	 * commit.
+	 */
+	for (i = items.nr - 1; i >= 0; i--) {
+		unsigned long bufsize;
+		const char *p;
+		const struct object_id *oid = items.oid + i;
+
+		this = lookup_commit_reference(the_repository, oid);
+		buffer = get_commit_buffer(this, &bufsize);
+		if (!buffer) {
+			res = -1;
+			error(_("cannot read commit buffer for %s"), oid_to_hex(oid));
+			goto out;
+		}
+
+		p = memmem(buffer, bufsize, "\n\n", 2);
+		if (!p) {
+			res = -1;
+			error(_("cannot parse commit %s"), oid_to_hex(oid));
+			goto out;
+		}
+
+		p += 2;
+		msg = xmemdupz(p, bufsize - (p - buffer));
+		unuse_commit_buffer(this, buffer);
+		buffer = NULL;
+
+		if (do_store_stash(oid, msg, 1)) {
+			res = -1;
+			error(_("cannot save the stash for %s"), oid_to_hex(oid));
+			goto out;
+		}
+		FREE_AND_NULL(msg);
+	}
+out:
+	if (this && buffer)
+		unuse_commit_buffer(this, buffer);
+	oid_array_clear(&items);
+	free(msg);
+
+	return res;
+}
+
+static int import_stash(int argc, const char **argv, const char *prefix)
+{
+	struct option options[] = {
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, prefix, options,
+			     git_stash_import_usage,
+			     PARSE_OPT_KEEP_DASHDASH);
+
+	if (argc != 1) {
+		usage_with_options(git_stash_import_usage, options);
+		return -1;
+	}
+
+	return do_import_stash(argv[0]);
+}
+
 static int do_export_stash(const char *ref, int argc, const char **argv)
 {
 	struct object_id base;
@@ -2000,6 +2103,8 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
 		return !!save_stash(argc, argv, prefix);
 	else if (!strcmp(argv[0], "export"))
 		return !!export_stash(argc, argv, prefix);
+	else if (!strcmp(argv[0], "import"))
+		return !!import_stash(argc, argv, prefix);
 	else if (*argv[0] != '-')
 		usage_msg_optf(_("unknown subcommand: %s"),
 			       git_stash_usage, options, argv[0]);
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index b149e2af44..03607a5a38 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -10,6 +10,13 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
+test_expect_success 'setup' '
+	test_oid_cache <<-EOF
+	export_base sha1:73c9bab443d1f88ac61aa533d2eeaaa15451239c
+	export_base sha256:f210fa6346e3e2ce047bdb570426b17075980c1ac01fec8fc4b75bd3ab4bcfe4
+	EOF
+'
+
 test_expect_success 'usage on cmd and subcommand invalid option' '
 	test_expect_code 129 git stash --invalid-option 2>usage &&
 	grep "or: git stash" usage &&
@@ -1295,6 +1302,62 @@ test_expect_success 'stash --keep-index with file deleted in index does not resu
 	test_path_is_missing to-remove
 '
 
+test_expect_success 'stash export and import round-trip stashes' '
+	git reset &&
+	>untracked &&
+	>tracked1 &&
+	>tracked2 &&
+	git add tracked* &&
+	git stash -- &&
+	>subdir/untracked &&
+	>subdir/tracked1 &&
+	>subdir/tracked2 &&
+	git add subdir/tracked* &&
+	git stash --include-untracked -- subdir/ &&
+	git tag t-stash0 stash@{0} &&
+	git tag t-stash1 stash@{1} &&
+	simple=$(git stash export --print) &&
+	git stash clear &&
+	git stash import "$simple" &&
+	test_cmp_rev stash@{0} t-stash0 &&
+	test_cmp_rev stash@{1} t-stash1 &&
+	git stash export --to-ref refs/heads/foo &&
+	git stash clear &&
+	git stash import foo &&
+	test_cmp_rev stash@{0} t-stash0 &&
+	test_cmp_rev stash@{1} t-stash1
+'
+
+test_expect_success 'stash import appends commits' '
+	git log --format=oneline -g refs/stash >out &&
+	cat out out >out2 &&
+	git stash import refs/heads/foo &&
+	git log --format=oneline -g refs/stash >actual &&
+	test_line_count = $(wc -l <out2) actual
+'
+
+test_expect_success 'stash export can accept specified stashes' '
+	git stash clear &&
+	git stash import foo &&
+	git stash export --to-ref bar stash@{1} stash@{0} &&
+	git stash clear &&
+	git stash import bar &&
+	test_cmp_rev stash@{1} t-stash0 &&
+	test_cmp_rev stash@{0} t-stash1 &&
+	git log --format=oneline -g refs/stash >actual &&
+	test_line_count = 2 actual
+'
+
+test_expect_success 'stash can import and export zero stashes' '
+	git stash clear &&
+	git stash export --to-ref baz &&
+	test_cmp_rev "$(test_oid empty_tree)" baz: &&
+	test_cmp_rev "$(test_oid export_base)" baz &&
+	test_must_fail git rev-parse baz^1 &&
+	git stash import baz &&
+	test_must_fail git rev-parse refs/stash
+'
+
 test_expect_success 'stash apply should succeed with unmodified file' '
 	echo base >file &&
 	git add file &&
Previous: brian m. carlsonNext: Jonathan Tan
Message 66 of 76 in “Importing and exporting stashes to refs”
  1. 0/6 Importing and exporting stashes to refsbrian m. carlson, Mar 10, 2022
  2. 2/6 builtin/stash: fill in all commit databrian m. carlson, Mar 10, 2022
  3. Junio C HamanoMar 16, 2022
  4. 1/6 builtin/stash: factor out generic function to look up stash infobrian m. carlson, Mar 10, 2022
  5. 3/6 object-name: make get_oid quietly return an errorbrian m. carlson, Mar 10, 2022
  6. Junio C HamanoMar 16, 2022
  7. Drew StoleeMar 16, 2022
  8. brian m. carlsonMar 16, 2022
  9. 4/6 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Mar 10, 2022
  10. Ævar Arnfjörð BjarmasonMar 11, 2022
  11. Phillip WoodMar 14, 2022
  12. Phillip WoodMar 15, 2022
  13. brian m. carlsonMar 16, 2022
  14. C99 %zu support (on MSVC) (was: [PATCH 4/6] builtin/stash: provide a way to export stashes to a ref)Ævar Arnfjörð Bjarmason, Mar 18, 2022
  15. Phillip WoodMar 18, 2022
  16. Johannes SchindelinMar 24, 2022
  17. ssize_t portability (was: [PATCH 4/6] builtin/stash: provide a way to export stashes to a ref)Ævar Arnfjörð Bjarmason, Mar 18, 2022
  18. Junio C HamanoMar 16, 2022
  19. 6/6 doc: add stash export and import to docsbrian m. carlson, Mar 10, 2022
  20. Junio C HamanoMar 16, 2022
  21. Junio C HamanoMar 16, 2022
  22. 5/6 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Mar 10, 2022
  23. Junio C HamanoMar 16, 2022
  24. brian m. carlsonMar 16, 2022
  25. Junio C HamanoMar 10, 2022
  26. brian m. carlsonMar 10, 2022
  27. Junio C HamanoMar 10, 2022
  28. brian m. carlsonMar 10, 2022
  29. 0/4 Importing and exporting stashes to refsbrian m. carlson, Mar 29, 2022
  30. 2/4 builtin/stash: factor out revision parsing into a functionbrian m. carlson, Mar 29, 2022
  31. 1/4 object-name: make get_oid quietly return an errorbrian m. carlson, Mar 29, 2022
  32. 4/4 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Mar 29, 2022
  33. 3/4 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Mar 29, 2022
  34. Junio C HamanoMar 30, 2022
  35. brian m. carlsonMar 30, 2022
  36. Ævar Arnfjörð BjarmasonMar 31, 2022
  37. Junio C HamanoMar 31, 2022
  38. brian m. carlsonApr 5, 2022
  39. Ævar Arnfjörð BjarmasonApr 6, 2022
  40. Junio C HamanoApr 6, 2022
  41. Ævar Arnfjörð BjarmasonMar 31, 2022
  42. brian m. carlsonApr 5, 2022
  43. Junio C HamanoMar 31, 2022
  44. Ævar Arnfjörð BjarmasonMar 31, 2022
  45. 0/4 Importing and exporting stashes to refsbrian m. carlson, Apr 3, 2022
  46. 1/4 object-name: make get_oid quietly return an errorbrian m. carlson, Apr 3, 2022
  47. 2/4 builtin/stash: factor out revision parsing into a functionbrian m. carlson, Apr 3, 2022
  48. Phillip WoodApr 4, 2022
  49. 4/4 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Apr 3, 2022
  50. Ævar Arnfjörð BjarmasonApr 4, 2022
  51. brian m. carlsonApr 5, 2022
  52. Ævar Arnfjörð BjarmasonApr 6, 2022
  53. 3/4 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Apr 3, 2022
  54. Ævar Arnfjörð BjarmasonApr 4, 2022
  55. Junio C HamanoApr 4, 2022
  56. Junio C HamanoApr 4, 2022
  57. Ævar Arnfjörð BjarmasonApr 4, 2022
  58. brian m. carlsonApr 5, 2022
  59. 0/4 Importing and exporting stashes to refsbrian m. carlson, Apr 7, 2022
  60. 3/4 builtin/stash: provide a way to export stashes to a refbrian m. carlson, Apr 7, 2022
  61. Ævar Arnfjörð BjarmasonApr 13, 2022
  62. Ævar Arnfjörð BjarmasonApr 13, 2022
  63. Ævar Arnfjörð BjarmasonApr 13, 2022
  64. 2/4 builtin/stash: factor out revision parsing into a functionbrian m. carlson, Apr 7, 2022
  65. 1/4 object-name: make get_oid quietly return an errorbrian m. carlson, Apr 7, 2022
  66. 4/4 builtin/stash: provide a way to import stashes from a refbrian m. carlson, Apr 7, 2022
  67. Jonathan TanApr 12, 2022
  68. brian m. carlsonApr 13, 2022
  69. Jonathan TanApr 13, 2022
  70. Ævar Arnfjörð BjarmasonApr 13, 2022
  71. Jonathan TanApr 13, 2022
  72. Junio C HamanoApr 13, 2022
  73. brian m. carlsonApr 13, 2022
  74. Junio C HamanoApr 13, 2022
  75. Ævar Arnfjörð BjarmasonApr 13, 2022
  76. Ævar Arnfjörð BjarmasonApr 13, 2022

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.