[sink] del_aubio_sink argument can be null

Most del_ methods in aubio do not check if their argument is NULL, but
del_aubio_sink used to, so we keep it this way to avoid breaking
existing programs.

diff --git a/src/io/sink.c b/src/io/sink.c
index f8ac5fd..f3f56a3 100644 (file)
--- a/src/io/sink.c
+++ b/src/io/sink.c
@@ -136,7 +136,7 @@ uint_t aubio_sink_close(aubio_sink_t *s) {
 
 void del_aubio_sink(aubio_sink_t * s) {
   AUBIO_ASSERT(s);
-  if (s->s_del && s->sink)
+  if (s && s->s_del && s->sink)
     s->s_del((void *)s->sink);
   AUBIO_FREE(s);
 }