srtpdec: fix "srtp-key" check

The original code was:

if (!gst_structure_get (s, "srtp-key", GST_TYPE_BUFFER, &buf, NULL) || !buf) {
  goto error;
} else {
  stream->key = buf;
}

So use "srtp-key" if it is set so a non NULL buffer. The condition was
incorrectly inverted in ad7ffe64a66ab48d81671651031c449149db4973 to:

if (gst_structure_get (s, "srtp-key", GST_TYPE_BUFFER, &buf, NULL) || !buf) {
  stream->key = buf;
} ...

Fix the condition so it works as originally intended and avoid accessing
'buf' uninitialised.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4423>

diff --git a/subprojects/gst-plugins-bad/ext/srtp/gstsrtpdec.c b/subprojects/gst-plugins-bad/ext/srtp/gstsrtpdec.c
index 2467f1b..591bfeb 100644 (file)
--- a/subprojects/gst-plugins-bad/ext/srtp/gstsrtpdec.c
+++ b/subprojects/gst-plugins-bad/ext/srtp/gstsrtpdec.c
@@ -606,7 +606,7 @@ get_stream_from_caps (GstSrtpDec * filter, GstCaps * caps, guint32 ssrc)
     goto error;
   }
 
-  if (gst_structure_get (s, "srtp-key", GST_TYPE_BUFFER, &buf, NULL) || !buf) {
+  if (gst_structure_get (s, "srtp-key", GST_TYPE_BUFFER, &buf, NULL) && buf) {
 #ifdef HAVE_SRTP2
     GstBuffer *mki = NULL;
     guint i;