From 0ff919e87a08b7ab81507917ca55eb613296d043 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Fri, 6 Dec 2024 16:45:13 +0100 Subject: [PATCH] object-name: fix reversed ordering with ":/" revisions Recently it was reported [1] that "look for the youngest commit reachable from any ref with log message that match the given pattern" syntax (i.e. ':/') started to return results in reverse recency order. This regression was introduced in Git v2.47.0 and is caused by a memory leak fix done in 57fb139b5e (object-name: fix leaking commit list items, 2024-08-01). The intent of the identified commit is to stop modifying the commit list provided by the caller such that the caller can properly free all commit list items, including those that the called function might potentially remove from the list. This was done by creating a copy of the passed-in commit list and modifying this copy instead of the caller-provided list. We already knew to create such a copy beforehand with the `backup` list, which was used to clear the `ONELINE_SEEN` commit mark after we were done. So the refactoring simply renamed that list to `copy` and started to operate on that list instead. There is a gotcha though: the backup list, and thus now also the copied list, is always being prepended to, so the resulting list is in reverse order! The end result is that we pop commits from the wrong end of the commit list, returning commits in reverse recency order. Fix the bug by appending to the list instead. [1]: Reported-by: Aarni Koskela Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- object-name.c | 4 ++-- t/t1500-rev-parse.sh | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/object-name.c b/object-name.c index 240a93e7ce..4c50559ee8 100644 --- a/object-name.c +++ b/object-name.c @@ -1393,7 +1393,7 @@ static int get_oid_oneline(struct repository *r, const char *prefix, struct object_id *oid, const struct commit_list *list) { - struct commit_list *copy = NULL; + struct commit_list *copy = NULL, **copy_tail = © const struct commit_list *l; int found = 0; int negative = 0; @@ -1415,7 +1415,7 @@ static int get_oid_oneline(struct repository *r, for (l = list; l; l = l->next) { l->item->object.flags |= ONELINE_SEEN; - commit_list_insert(l->item, ©); + copy_tail = &commit_list_insert(l->item, copy_tail)->next; } while (copy) { const char *p, *buf; diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh index 30c31918fd..42c4a63cb9 100755 --- a/t/t1500-rev-parse.sh +++ b/t/t1500-rev-parse.sh @@ -310,4 +310,19 @@ test_expect_success '--short= truncates to the actual hash length' ' test_cmp expect actual ' +test_expect_success ':/ and HEAD^{/} favor more recent matching commits' ' + test_when_finished "rm -rf repo" && + git init repo && + ( + cd repo && + test_commit common-old && + test_commit --no-tag common-new && + git rev-parse HEAD >expect && + git rev-parse :/common >actual && + test_cmp expect actual && + git rev-parse HEAD^{/common} >actual && + test_cmp expect actual + ) +' + test_done