merge: apply autostash if fast-forward fails

phil-blain · gitster · commit 12510bd5da61 · 2021-07-23T15:45:38.000-07:00
Since 'git merge' learned '--autostash' in a03b555 (merge: teach --autostash option, 2020-04-07), 'cmd_merge', in the fast-forward case, calls 'create_autostash' before calling 'checkout_fast_forward' if '--autostash' is given. However, if 'checkout_fast_forward' fails, the autostash is not applied to the working tree, nor saved in the stash list, since the code simply calls 'goto done'. Be more helpful to the user by applying the autostash in that case. An easy way to test a failing fast-forward is when we are merging a branch that has a tracked file that conflicts with an untracked file in the working tree. 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
@@ -1560,6 +1560,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 					  &head_commit->object.oid,
 					  &commit->object.oid,
 					  overwrite_ignore)) {
+			apply_autostash(git_path_merge_autostash(the_repository));
 			ret = 1;
 			goto done;
 		}
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
@@ -122,6 +122,8 @@ test_expect_success 'setup' '
 	c0=$(git rev-parse HEAD) &&
 	cp file.1 file &&
 	git add file &&
+	cp file.1 other &&
+	git add other &&
 	test_tick &&
 	git commit -m "commit 1" &&
 	git tag c1 &&
@@ -711,6 +713,15 @@ test_expect_success 'fast-forward merge with --autostash' '
 	test_cmp result.1-5 file
 '
 
+test_expect_success 'failed fast-forward merge with --autostash' '
+	git reset --hard c0 &&
+	git merge-file file file.orig file.5 &&
+	cp file.5 other &&
+	test_must_fail git merge --autostash c1 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp file.5 file
+'
+
 test_expect_success 'octopus merge with --autostash' '
 	git reset --hard c1 &&
 	git merge-file file file.orig file.3 &&

Original file line number	Diff line number	Diff line change
`@@ -1560,6 +1560,7 @@ int cmd_merge(int argc, const char *argv, const char prefix)`
`1560`	`1560`	`&head_commit->object.oid,`
`1561`	`1561`	`&commit->object.oid,`
`1562`	`1562`	`overwrite_ignore)) {`
	`1563`	`+ apply_autostash(git_path_merge_autostash(the_repository));`
`1563`	`1564`	`ret = 1;`
`1564`	`1565`	`goto done;`
`1565`	`1566`	`}`