In 7c117184d7 ("bisect: fix off-by-one error in `best_bisection_sorted()`", 2017-11-05) the more careful logic dealing with freeing p->next in 50e62a8e70 ("rev-list: implement --bisect-all", 2007-10-22) was removed. Restore the more careful check to avoid segfaulting. Ideally this would come with a test case, but we don't have steps to reproduce this, only a backtrace from gdb pointing to this being the issue. Reported-by: Yasushi SHOJI <yasushi.shoji@xxxxxxxxx> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> --- bisect.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/bisect.c b/bisect.c index 0fca17c02b..2f3008b078 100644 --- a/bisect.c +++ b/bisect.c @@ -229,8 +229,10 @@ static struct commit_list *best_bisection_sorted(struct commit_list *list, int n if (i < cnt - 1) p = p->next; } - free_commit_list(p->next); - p->next = NULL; + if (p) { + free_commit_list(p->next); + p->next = NULL; + } strbuf_release(&buf); free(array); return list; -- 2.15.1.424.g9478a66081