@leroysheep / BookAlchemy / commits / bbd445d5ef

tag: "git tag" refuses to use HEAD as a tagname

Even though the plumbing level allows you to create refs/tags/HEAD and refs/heads/HEAD, doing so makes it confusing within the context of the UI Git Porcelain commands provides. Just like we prevent a branch from getting called "HEAD" at the Porcelain layer (i.e. "git branch" command), teach "git tag" to refuse to create a tag "HEAD". With a few new tests, we make sure that - "git tag HEAD" and "git tag -a HEAD" are rejected - "git update-ref refs/tags/HEAD" is still allowed (this is a deliberate design decision to allow others to create their own UI on top of Git infrastructure that may be different from our UI). - "git tag -d HEAD" can remove refs/tags/HEAD to recover from an mistake. Helped-by: Jeff King <peff@peff.net> Helped-by: Rubén Justo <rjusto@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Junio C Hamano committed Dec 3, 2024 at 11:32 UTC bbd445d5efd415d43ac6102a3e9541b9ac4f0329
2 files changed +13 -1
refs.c
+1 -1
index a24bfe3845..01ef2a3093 100644 --- a/refs.c +++ b/refs.c @@ -735,7 +735,7 @@ int check_branch_ref(struct strbuf *sb, const char *name) int check_tag_ref(struct strbuf *sb, const char *name) { - if (name[0] == '-') + if (name[0] == '-' || !strcmp(name, "HEAD")) return -1; strbuf_reset(sb);
t/t7004-tag.sh
+12
index b1316e62f4..34d34b0dfb 100755 --- a/t/t7004-tag.sh +++ b/t/t7004-tag.sh @@ -91,6 +91,18 @@ test_expect_success 'creating a tag using default HEAD should succeed' ' test_must_fail git reflog exists refs/tags/mytag ' +test_expect_success 'HEAD is forbidden as a tagname' ' + test_when_finished "git update-ref --no-deref -d refs/tags/HEAD || :" && + test_must_fail git tag HEAD && + test_must_fail git tag -a -m "useless" HEAD +' + +test_expect_success '"git tag" can remove a tag named HEAD' ' + test_when_finished "git update-ref --no-deref -d refs/tags/HEAD || :" && + git update-ref refs/tags/HEAD HEAD && + git tag -d HEAD +' + test_expect_success 'creating a tag with --create-reflog should create reflog' ' git log -1 \ --format="format:tag: tagging %h (%s, %cd)%n" \