merge: apply autostash if merge strategy fails

phil-blain · gitster · commit e082631e51eb · 2021-07-23T15:45:40.000-07:00
Since 'git merge' learned '--autostash' in a03b555 (merge: teach --autostash option, 2020-04-07), 'cmd_merge', once it is determined that we have to create a merge commit, calls 'create_autostash' if '--autostash' is given. As explained in a03b555, and made more abvious by the tests added in that commit, the autostash is then applied if the merge succeeds, either directly or by committing (after conflict resolution or if '--no-commit' was given), or if the merge is aborted with 'git merge --abort'. In some other cases, like the user calling 'git reset --merge' or 'git merge --quit', the autostash is not applied, but saved in the stash list. However, there exists a scenario that creates an autostash but does not apply nor save it to the stash list: if the chosen merge strategy completely fails to handle the merge, i.e. 'try_merge_strategy' returns 2. Apply the autostash in that case also. An easy way to test that is to try to merge more than two commits but explicitely ask for the 'recursive' merge strategy. Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/merge.c b/builtin/merge.c
@@ -1709,6 +1709,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		else
 			fprintf(stderr, _("Merge with strategy %s failed.\n"),
 				use_strategies[0]->name);
+		apply_autostash(git_path_merge_autostash(the_repository));
 		ret = 2;
 		goto done;
 	} else if (best_strategy == wt_strategy)
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
@@ -732,6 +732,14 @@ test_expect_success 'octopus merge with --autostash' '
 	test_cmp result.1-3-5-9 file
 '
 
+test_expect_success 'failed merge (exit 2) with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.5 &&
+	test_must_fail git merge -s recursive --autostash c2 c3 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp result.1-5 file
+'
+
 test_expect_success 'conflicted merge with --autostash, --abort restores stash' '
 	git reset --hard c3 &&
 	cp file.1 file &&
