From 4654134976fd4d80ea664c159f798f21c7917d8c Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Tue, 25 Oct 2022 16:29:34 -0700 Subject: [PATCH] negotiator/skipping: avoid stack overflow mark_common() in negotiator/skipping.c may overflow the stack due to recursive function calls. Avoid this by instead recursing using a heap-allocated data structure. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- negotiator/skipping.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/negotiator/skipping.c b/negotiator/skipping.c index c4398f5ae1..0f5ac48e87 100644 --- a/negotiator/skipping.c +++ b/negotiator/skipping.c @@ -86,21 +86,26 @@ static int clear_marks(const char *refname, const struct object_id *oid, /* * Mark this SEEN commit and all its SEEN ancestors as COMMON. */ -static void mark_common(struct data *data, struct commit *c) +static void mark_common(struct data *data, struct commit *seen_commit) { - struct commit_list *p; + struct prio_queue queue = { NULL }; + struct commit *c; - if (c->object.flags & COMMON) - return; - c->object.flags |= COMMON; - if (!(c->object.flags & POPPED)) - data->non_common_revs--; + prio_queue_put(&queue, seen_commit); + while ((c = prio_queue_get(&queue))) { + struct commit_list *p; + if (c->object.flags & COMMON) + return; + c->object.flags |= COMMON; + if (!(c->object.flags & POPPED)) + data->non_common_revs--; - if (!c->object.parsed) - return; - for (p = c->parents; p; p = p->next) { - if (p->item->object.flags & SEEN) - mark_common(data, p->item); + if (!c->object.parsed) + return; + for (p = c->parents; p; p = p->next) { + if (p->item->object.flags & SEEN) + prio_queue_put(&queue, p->item); + } } }