refs: prevent accidental NULL dereference in write_pseudoref
Several of the refs functions take NULL to indicate that the ref is not
to be updated. If refs_update_ref were called with a NULL new object
ID, we could pass that NULL pointer to write_pseudoref, which would then
segfault when it dereferenced it. Instead, simply return successfully,
since if we don't want to update the pseudoref, there's nothing to do.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/refs.c b/refs.c
index edd2004..91c2af7 100644
--- a/refs.c
+++ b/refs.c
@@ -583,6 +583,9 @@ static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
struct strbuf buf = STRBUF_INIT;
int ret = -1;
+ if (!oid)
+ return 0;
+
strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
filename = git_path("%s", pseudoref);
