fetch set_head: fix non-mirror remotes in bare repositories

In b1b713f722 (fetch set_head: handle mirrored bare repositories,
2024-11-22) it was implicitly assumed that all remotes will be mirrors
in a bare repository, thus fetching a non-mirrored remote could lead to
HEAD pointing to a non-existent reference. Make sure we only overwrite
HEAD if we are in a bare repository and fetching from a mirror.
Otherwise, proceed as normally, and create
refs/remotes/<nonmirrorremote>/HEAD instead.

Reported-by: Christian Hesse <list@eworm.de>
Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 3167b055d12058ab08e33d35a378717ef22f72eb..1c740d5aac32df93dd04818a4dad008565feb151 100644 (file)
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1619,7 +1619,7 @@ static void report_set_head(const char *remote, const char *head_name,
 
 static int set_head(const struct ref *remote_refs, struct remote *remote)
 {
-       int result = 0, create_only, is_bare, was_detached;
+       int result = 0, create_only, baremirror, was_detached;
        struct strbuf b_head = STRBUF_INIT, b_remote_head = STRBUF_INIT,
                      b_local_head = STRBUF_INIT;
        int follow_remote_head = remote->follow_remote_head;
@@ -1655,9 +1655,9 @@ static int set_head(const struct ref *remote_refs, struct remote *remote)
 
        if (!head_name)
                goto cleanup;
-       is_bare = is_bare_repository();
-       create_only = follow_remote_head == FOLLOW_REMOTE_ALWAYS ? 0 : !is_bare;
-       if (is_bare) {
+       baremirror = is_bare_repository() && remote->mirror;
+       create_only = follow_remote_head == FOLLOW_REMOTE_ALWAYS ? 0 : !baremirror;
+       if (baremirror) {
                strbuf_addstr(&b_head, "HEAD");
                strbuf_addf(&b_remote_head, "refs/heads/%s", head_name);
        } else {
@@ -1665,7 +1665,7 @@ static int set_head(const struct ref *remote_refs, struct remote *remote)
                strbuf_addf(&b_remote_head, "refs/remotes/%s/%s", remote->name, head_name);
        }
                /* make sure it's valid */
-       if (!is_bare && !refs_ref_exists(refs, b_remote_head.buf)) {
+       if (!baremirror && !refs_ref_exists(refs, b_remote_head.buf)) {
                result = 1;
                goto cleanup;
        }

diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index 519f7973e3128769ec19531557318cc886e330d9..66e373f71dbaba67badf783e9753fddc43de5e68 100755 (executable)
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -589,6 +589,16 @@ test_expect_success 'add --mirror setting HEAD' '
        )
 '
 
+test_expect_success 'non-mirror fetch does not interfere with mirror' '
+       test_when_finished rm -rf headnotmain &&
+       (
+               git init --bare -b notmain headnotmain &&
+               cd headnotmain &&
+               git remote add -f other ../two &&
+               test "$(git symbolic-ref HEAD)" = "refs/heads/notmain"
+       )
+'
+
 test_expect_success 'add --mirror=fetch' '
        mkdir mirror-fetch &&
        git init -b main mirror-fetch/parent &&

diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index 2d9587059f508362e2cf5f52716ecc3f796da9c1..c9d7b46c877c7125e007af6f2f837c7ff0dec56f 100755 (executable)
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -84,6 +84,23 @@ test_expect_success "fetch test remote HEAD" '
        branch=$(git rev-parse refs/remotes/origin/main) &&
        test "z$head" = "z$branch"'
 
+test_expect_success "fetch test remote HEAD in bare repository" '
+       test_when_finished rm -rf barerepo &&
+       (
+               cd "$D" &&
+               git init --bare barerepo &&
+               cd barerepo &&
+               git remote add upstream ../two &&
+               git fetch upstream &&
+               git rev-parse --verify refs/remotes/upstream/HEAD &&
+               git rev-parse --verify refs/remotes/upstream/main &&
+               head=$(git rev-parse refs/remotes/upstream/HEAD) &&
+               branch=$(git rev-parse refs/remotes/upstream/main) &&
+               test "z$head" = "z$branch"
+       )
+'
+
+
 test_expect_success "fetch test remote HEAD change" '
        cd "$D" &&
        cd two &&