[PATCH] Fix count-delta overcounting

diff --git a/count-delta.c b/count-delta.c
index 3bcc205f5131a168ac71d9b011d11920e25736f8..e10c832a758f49e9117a3456686d54f8b94ce10b 100644 (file)
--- a/count-delta.c
+++ b/count-delta.c
@@ -88,5 +88,8 @@ unsigned long count_delta(void *delta_buf, unsigned long delta_size)
        /* delete size is what was _not_ copied from source.
         * edit size is that and literal additions.
         */
+       if (src_size + added_literal < copied_from_source)
+               /* we ended up overcounting and underflowed */
+               return 0;
        return (src_size - copied_from_source) + added_literal;
 }