stun: Fix potential zero-length memset() call

GCC warns about this. Might as well prevent the warning.

1 files changed, 5 insertions, 3 deletions

diff --git a/stun/stunmessage.c b/stun/stunmessage.c
index b9c54e3..3e55368 100644
--- a/stun/stunmessage.c
+++ b/stun/stunmessage.c
@@ -357,9 +357,11 @@ stun_message_append (StunMessage *msg, StunAttribute type, size_t length)
      * to a multiple of 4 for compatibility with old RFC3489 */
     a = stun_setw (a, stun_message_has_cookie (msg) ? length : stun_align (length));
 
-    /* Add padding if needed */
-    memset (a + length, ' ', stun_padding (length));
-    mlen += stun_padding (length);
+    /* Add padding if needed. Avoid a zero-length memset() call. */
+    if (stun_padding (length) > 0) {
+      memset (a + length, ' ', stun_padding (length));
+      mlen += stun_padding (length);
+    }
   }
 
   mlen +=  4 + length;