Addressed PR comments.

1 files changed, 1 insertions, 0 deletions

diff --git a/upb/sink.c b/upb/sink.c
index ed0972b..e6ede49 100644
--- a/upb/sink.c
+++ b/upb/sink.c
@@ -39,6 +39,7 @@ static size_t upb_bufsink_string(void *_sink, const void *hd, const char *ptr,
   upb_bufsink *sink = _sink;
   size_t new_size = sink->size;
 
+  UPB_ASSERT(new_size > 0);
   UPB_UNUSED(hd);
   UPB_UNUSED(handle);