From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 30 Jun 2026 19:59:15 +0000 (-0700)
Subject: Merge branch 'kk/commit-reach-find-all-fix' into jch
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4f4a824c81d733beba908b3adec157d1cf13de7d;p=thirdparty%2Fgit.git

Merge branch 'kk/commit-reach-find-all-fix' into jch

The early-exit optimization in paint_down_to_common() has been gated
on the queue being generation-ordered. This fixes a bug where git
merge-base (without --all) could return incorrect results on
repositories with v1 commit graphs and clock skew.

* kk/commit-reach-find-all-fix:
  commit-reach: guard !FIND_ALL early exit with generation ordering check
  t6600: add test for merge-base early exit with clock skew
---

4f4a824c81d733beba908b3adec157d1cf13de7d
diff --cc commit-reach.c
index 5df471a313,ee4b7b6925..708798a39b
--- a/commit-reach.c
+++ b/commit-reach.c
@@@ -104,15 -57,16 +104,18 @@@ static int paint_down_to_common(struct 
  				enum merge_base_flags mb_flags,
  				struct commit_list **result)
  {
 -	struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 +	struct nonstale_queue queue = {
 +		{ compare_commits_by_gen_then_commit_date }
 +	};
  	int i;
+ 	int gen_ordered = 1;
  	timestamp_t last_gen = GENERATION_NUMBER_INFINITY;
  	struct commit_list **tail = result;
  
- 	if (!min_generation && !corrected_commit_dates_enabled(r))
+ 	if (!min_generation && !corrected_commit_dates_enabled(r)) {
 -		queue.compare = compare_commits_by_commit_date;
 +		queue.pq.compare = compare_commits_by_commit_date;
+ 		gen_ordered = 0;
+ 	}
  
  	one->object.flags |= PARENT1;
  	if (!n) {