path: root/object-refs.c
diff options
authorLinus Torvalds <>2006-09-04 15:34:12 (GMT)
committerJunio C Hamano <>2006-09-04 22:24:10 (GMT)
commit5d44cd1c8b27fb677fedc886303d38b19fbb07f7 (patch)
treec77ca9272226511f3730f168400aae621ddf7c71 /object-refs.c
parentf2e609473cb4aeb3884b7dd57a3a652df4e5edcf (diff)
Fix git-fsck-objects SIGSEGV/divide-by-zero
If you try to fsck a repository that isn't entirely empty, but that has no inter-object references (ie all the objects are blobs, and don't refer to anything else), git-fsck-objects currently fails. This probably cannot happen in practice, but can be tested with something like git init-db touch dummy git add dummy git fsck-objects where the fsck will die by a divide-by-zero when it tries to look up the references from the one object it found (hash_obj() will do a modulus by refs_hash_size). On some other archiectures (ppc, sparc) the divide-by-zero will go unnoticed, and we'll instead SIGSEGV when we hit the "refs_hash[j]" access. So move the test that should protect against this from mark_reachable() into lookup_object_refs(), which incidentally in the process also fixes mark_reachable() itself (it used to not mark the one object that _was_ reachable, because it decided that it had no refs too early). Signed-off-by: Linus Torvalds <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'object-refs.c')
1 files changed, 5 insertions, 4 deletions
diff --git a/object-refs.c b/object-refs.c
index b0034e4..98ea100 100644
--- a/object-refs.c
+++ b/object-refs.c
@@ -55,9 +55,13 @@ static void add_object_refs(struct object *obj, struct object_refs *ref)
struct object_refs *lookup_object_refs(struct object *obj)
- int j = hash_obj(obj, refs_hash_size);
struct object_refs *ref;
+ int j;
+ /* nothing to lookup */
+ if (!refs_hash_size)
+ return NULL;
+ j = hash_obj(obj, refs_hash_size);
while ((ref = refs_hash[j]) != NULL) {
if (ref->base == obj)
@@ -125,9 +129,6 @@ void mark_reachable(struct object *obj, unsigned int mask)
if (!track_object_refs)
die("cannot do reachability with object refs turned off");
- /* nothing to lookup */
- if (!refs_hash_size)
- return;
/* If we've been here already, don't bother */
if (obj->flags & mask)