Merge branch 'ps/report-failure-from-git-stash' into maint-2.43

"git stash" sometimes was silent even when it failed due to
unwritable index file, which has been corrected.

* ps/report-failure-from-git-stash:
  builtin/stash: report failure to write to index

Author: gitster

builtin/stash.c

@@ -520,7 +520,7 @@ static void unstage_changes_unless_new(struct object_id *orig_tree)
 	repo_hold_locked_index(the_repository, &lock, LOCK_DIE_ON_ERROR);
 	if (write_locked_index(&the_index, &lock,
 			       COMMIT_LOCK | SKIP_IF_UNCHANGED))
-		die(_("Unable to write index."));
+		die(_("could not write index"));
 }
 
 static int do_apply_stash(const char *prefix, struct stash_info *info,
@@ -537,7 +537,7 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 	repo_read_index_preload(the_repository, NULL, 0);
 	if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET, 0, 0,
 					 NULL, NULL, NULL))
-		return -1;
+		return error(_("could not write index"));
 
 	if (write_index_as_tree(&c_tree, &the_index, get_index_file(), 0,
 				NULL))
@@ -1364,7 +1364,7 @@ static int do_create_stash(const struct pathspec *ps, struct strbuf *stash_msg_b
 	repo_read_index_preload(the_repository, NULL, 0);
 	if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET, 0, 0,
 					 NULL, NULL, NULL) < 0) {
-		ret = -1;
+		ret = error(_("could not write index"));
 		goto done;
 	}
 
@@ -1555,7 +1555,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 
 	if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET, 0, 0,
 					 NULL, NULL, NULL)) {
-		ret = -1;
+		ret = error(_("could not write index"));
 		goto done;
 	}
 

t/t3903-stash.sh

@@ -1516,4 +1516,56 @@ test_expect_success 'restore untracked files even when we hit conflicts' '
 	)
 '
 
+test_expect_success 'stash create reports a locked index' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit A A.file &&
+		echo change >A.file &&
+		touch .git/index.lock &&
+
+		cat >expect <<-EOF &&
+		error: could not write index
+		EOF
+		test_must_fail git stash create 2>err &&
+		test_cmp expect err
+	)
+'
+
+test_expect_success 'stash push reports a locked index' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit A A.file &&
+		echo change >A.file &&
+		touch .git/index.lock &&
+
+		cat >expect <<-EOF &&
+		error: could not write index
+		EOF
+		test_must_fail git stash push 2>err &&
+		test_cmp expect err
+	)
+'
+
+test_expect_success 'stash apply reports a locked index' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit A A.file &&
+		echo change >A.file &&
+		git stash push &&
+		touch .git/index.lock &&
+
+		cat >expect <<-EOF &&
+		error: could not write index
+		EOF
+		test_must_fail git stash apply 2>err &&
+		test_cmp expect err
+	)
+'
+
 test_done