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 <jonathantanmy@xxxxxxxxxx>
---
This was observed at $DAYJOB.
To reviewers, you can check the diff with:
git show --color-moved-ws=allow-indentation-change --color-moved
to more clearly show which lines are new and which lines have only
changed indentation.
---
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);
+ }
}
}
--
2.38.0.135.g90850a2211-goog
