[v4,4/7] merge: fix save_state() to work when there are stat-dirty files

Commit Message

Elijah Newren July 22, 2022, 5:15 a.m. UTC

From: Elijah Newren <[e-mail]>

When there are stat-dirty files, but no files are modified,
`git stash create` exits with unsuccessful status.  This causes merge
to fail.  Copy some code from sequencer.c's create_autostash to refresh
the index first to avoid this problem.

Signed-off-by: Elijah Newren <[e-mail]>
---
 builtin/merge.c                          |  8 ++++++++
 t/t6424-merge-unrelated-index-changes.sh | 11 +++++++++++
 2 files changed, 19 insertions(+)

Patch

diff --git a/builtin/merge.c b/builtin/merge.c
index dec7375bf2a..4170c30317e 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -313,8 +313,16 @@  static int save_state(struct object_id *stash)
 	int len;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct strbuf buffer = STRBUF_INIT;
+	struct lock_file lock_file = LOCK_INIT;
+	int fd;
 	int rc = -1;
 
+	fd = repo_hold_locked_index(the_repository, &lock_file, 0);
+	refresh_cache(REFRESH_QUIET);
+	if (0 <= fd)
+		repo_update_index_if_able(the_repository, &lock_file);
+	rollback_lock_file(&lock_file);
+
 	strvec_pushl(&cp.args, "stash", "create", NULL);
 	cp.out = -1;
 	cp.git_cmd = 1;
diff --git a/t/t6424-merge-unrelated-index-changes.sh b/t/t6424-merge-unrelated-index-changes.sh
index 8b749e19083..3019d030e07 100755
--- a/t/t6424-merge-unrelated-index-changes.sh
+++ b/t/t6424-merge-unrelated-index-changes.sh
@@ -268,6 +268,17 @@  test_expect_success 'subtree' '
 	test_path_is_missing .git/MERGE_HEAD
 '
 
+test_expect_success 'avoid failure due to stat-dirty files' '
+	git reset --hard &&
+	git checkout B^0 &&
+
+	# Make "a" be stat-dirty
+	test-tool chmtime =+1 a &&
+
+	# stat-dirty file should not prevent stash creation in builtin/merge.c
+	git merge -s resolve -s recursive D^0
+'
+
 test_expect_success 'resolve && recursive && ort' '
 	git reset --hard &&
 	git checkout B^0 &&