allocations: test for overflow of requested size

Introduce some helper macros to test integer overflow from arithmetic
and set error message appropriately.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/oid.c b/src/oid.c
index 5d29200b6..9aac47db6 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -261,6 +261,7 @@ struct git_oid_shorten {
 
 static int resize_trie(git_oid_shorten *self, size_t new_size)
 {
+	GITERR_CHECK_ALLOC_MULTIPLY(new_size, sizeof(trie_node));
 	self->nodes = git__realloc(self->nodes, new_size * sizeof(trie_node));
 	GITERR_CHECK_ALLOC(self->nodes);