flac_afh: Check for possible integer overflows.

This is a callback function which should carefully check its inputs.

diff --git a/flac_afh.c b/flac_afh.c
index 1d0b3bf45dc60acd3f76288544803ee84f052338..ab71670568905135bc7a9a84f02098db169430c6 100644 (file)
--- a/flac_afh.c
+++ b/flac_afh.c
@@ -433,10 +433,10 @@ static size_t temp_write_cb(const void *ptr, size_t size, size_t nmemb,
        FLAC__IOHandle handle)
 {
        int ret, fd = *(int *)handle;
-       size_t n = size * nmemb; /* FIXME: possible overflow */
+       size_t n;
 
+       assert(!__builtin_mul_overflow(nmemb, size, &n));
        ret = write_all(fd, ptr, n);
-
        /*
         * libflac expects POSIX semantics: If an error occurs, or the end of
         * the file is reached, the return value is a short item count or zero.