@leroysheep / MovieWebApp / commits / 9c82ba86a0

rebase: skip branch symref aliases

git rebase --update-refs can finish rewriting the current branch and then fail while updating a local branch that is a symbolic ref. This can happen during a default-branch rename where refs/heads/main points at refs/heads/master while users migrate. The problem is a partially applied ref update: the main rebase has already succeeded when the later ref update fails. The sequencer queues updates from local branch decorations. Commit 106b6885c7 (rebase: ignore non-branch update-refs) filters out decorations such as HEAD and tags. A branch symref is still a local branch decoration, but refs_update_ref() dereferences it, so an alias to another branch duplicates the concrete branch update. Resolve local branch decorations before queuing them. Skip symrefs whose targets are under refs/heads/ so that only the concrete branch update is queued. Keep an owned copy of the resolved HEAD and skip the current branch before checked-out handling so later ref resolution cannot change the comparison. This prevents a successful rebase from being followed by a failed, partially applied ref update while preserving each alias as a symref. Signed-off-by: Son Luong Ngoc <sluongng@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Son Luong Ngoc committed Jul 22, 2026 at 08:15 UTC 9c82ba86a0c5e630d5defbe8118612fd5c5e4612
3 files changed +49 -13
sequencer.c
+32 -12
index 1ee4b2875b..17f5baab62 100644 --- a/sequencer.c +++ b/sequencer.c @@ -6445,32 +6445,50 @@ static int add_decorations_to_list(const struct commit *commit, struct todo_add_branch_context *ctx) { const struct name_decoration *decoration = get_name_decoration(&commit->object); - const char *head_ref = refs_resolve_ref_unsafe(get_main_ref_store(the_repository), - "HEAD", - RESOLVE_REF_READING, - NULL, - NULL); + struct ref_store *refs = get_main_ref_store(the_repository); + char *head_ref = refs_resolve_refdup(refs, "HEAD", + RESOLVE_REF_READING, + NULL, NULL); while (decoration) { struct todo_item *item; const char *path; + char *resolved_ref; + int flags = 0; size_t base_offset = ctx->buf->len; /* - * If the branch is the current HEAD, then it will be - * updated by the default rebase behavior. - * Exclude it from the list of refs to update, - * as well as any non-branch decorations. * Non-branch decorations may be present if the pretty format * includes "%d", which would have loaded all refs * into the global decoration table. */ - if ((head_ref && !strcmp(head_ref, decoration->name)) || - (decoration->type != DECORATION_REF_LOCAL)) { + if (decoration->type != DECORATION_REF_LOCAL) { + decoration = decoration->next; + continue; + } + + resolved_ref = refs_resolve_refdup(refs, decoration->name, + RESOLVE_REF_READING, + NULL, &flags); + if (resolved_ref && (flags & REF_ISSYMREF) && + starts_with(resolved_ref, "refs/heads/")) { + free(resolved_ref); + decoration = decoration->next; + continue; + } + + /* + * If the branch is the current HEAD, then it will be + * updated by the default rebase behavior. + */ + if (head_ref && !strcmp(head_ref, decoration->name)) { + free(resolved_ref); decoration = decoration->next; continue; } + path = branch_checked_out(decoration->name); + ALLOC_GROW(ctx->items, ctx->items_nr + 1, ctx->items_alloc); @@ -6478,7 +6496,7 @@ static int add_decorations_to_list(const struct commit *commit, memset(item, 0, sizeof(*item)); /* If the branch is checked out, then leave a comment instead. */ - if ((path = branch_checked_out(decoration->name))) { + if (path) { item->command = TODO_COMMENT; strbuf_commented_addf(ctx->buf, comment_line_str, "Ref %s checked out at '%s'\n", @@ -6498,9 +6516,11 @@ static int add_decorations_to_list(const struct commit *commit, item->arg_len = ctx->buf->len - base_offset; ctx->items_nr++; + free(resolved_ref); decoration = decoration->next; } + free(head_ref); return 0; }
t/t3400-rebase.sh
+1 -1
index c0c00fbb7b..be120bdcd1 100755 --- a/t/t3400-rebase.sh +++ b/t/t3400-rebase.sh @@ -471,7 +471,7 @@ test_expect_success 'git rebase --update-ref with core.commentChar and branch on GIT_SEQUENCE_EDITOR="cat >actual" git -c core.commentChar=% \ rebase -i --update-refs base && test_grep "% Ref refs/heads/wt-topic checked out at" actual && - test_grep "% Ref refs/heads/topic2 checked out at" actual + test_grep ! "% Ref refs/heads/topic2 checked out at" actual ' test_done
t/t3404-rebase-interactive.sh
+16
index 58b3bb0c27..b05d938846 100755 --- a/t/t3404-rebase-interactive.sh +++ b/t/t3404-rebase-interactive.sh @@ -1975,15 +1975,23 @@ test_expect_success '--update-refs ignores non-branch decorations' ' ) && grep ^update-ref todo >actual && test_write_lines "update-ref refs/heads/no-conflict-branch" >expect && + test_grep ! "^# Ref refs/heads/update-refs checked out" todo && test_cmp expect actual ' test_expect_success '--update-refs updates refs correctly' ' + test_when_finished " + test_might_fail git symbolic-ref -d refs/heads/no-conflict-branch-alias && + test_might_fail git symbolic-ref -d refs/heads/second-alias + " && git checkout -B update-refs no-conflict-branch && git branch -f base HEAD~4 && git branch -f first HEAD~3 && git branch -f second HEAD~3 && git branch -f third HEAD~1 && + git symbolic-ref refs/heads/no-conflict-branch-alias \ + refs/heads/no-conflict-branch && + git symbolic-ref refs/heads/second-alias refs/heads/second && test_commit extra2 fileX && git commit --amend --fixup=L && @@ -1991,8 +1999,16 @@ test_expect_success '--update-refs updates refs correctly' ' test_cmp_rev HEAD~3 refs/heads/first && test_cmp_rev HEAD~3 refs/heads/second && + test_cmp_rev HEAD~3 refs/heads/second-alias && test_cmp_rev HEAD~1 refs/heads/third && test_cmp_rev HEAD refs/heads/no-conflict-branch && + test_cmp_rev HEAD refs/heads/no-conflict-branch-alias && + test_write_lines refs/heads/no-conflict-branch >expect && + git symbolic-ref refs/heads/no-conflict-branch-alias >actual && + test_cmp expect actual && + test_write_lines refs/heads/second >expect && + git symbolic-ref refs/heads/second-alias >actual && + test_cmp expect actual && q_to_tab >expect <<-\EOF && Successfully rebased and updated refs/heads/update-refs.