res_pjsip_session: Make reschedule_reinvite check for NULL topologies

When the check for equal topologies was added to reschedule_reinvite()
it was assumed that both the pending and active media states would
actually have non-NULL topologies.  We since discovered this isn't
the case.

We now only test for equal topologies if both media states have
non-NULL topologies.  The logic had to be rearranged a bit to make
sure that we cloned the media states if their topologies were
non-NULL but weren't equal.

ASTERISK-29215

Change-Id: I61313cca7fc571144338aac826091791b87b6e17

diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index e319842383b8128776ac1e018724b4f77e3f2c14..3f61b63dcbf2c81f4ab2ad9d46e12a39531e8fcf 100644 (file)
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -4273,18 +4273,40 @@ static void reschedule_reinvite(struct ast_sip_session *session, ast_sip_session
        struct ast_sip_session_media_state *pending_media_state = NULL;
        struct ast_sip_session_media_state *active_media_state = NULL;
        const char *session_name = ast_sip_session_get_name(session);
+       int use_pending = 0;
+       int use_active = 0;
+
        SCOPE_ENTER(3, "%s\n", session_name);
 
-       /* If the two media state topologies are the same this means that the session refresh request
+       /*
+        * If the two media state topologies are the same this means that the session refresh request
         * did not specify a desired topology, so it does not care. If that is the case we don't even
-        * pass one in here resulting in the current topology being used.
+        * pass one in here resulting in the current topology being used.  It's possible though that
+        * either one of the topologies could be NULL so we have to test for that before we check for
+        * equality.
         */
-       if (!ast_stream_topology_equal(session->active_media_state->topology, session->pending_media_state->topology)) {
+
+       /* We only want to clone a media state if its topology is not null */
+       use_pending = session->pending_media_state->topology != NULL;
+       use_active = session->active_media_state->topology != NULL;
+
+       /*
+        * If both media states have topologies, we can test for equality.  If they're equal we're not going to
+        * clone either states.
+        */
+       if (use_pending && use_active && ast_stream_topology_equal(session->active_media_state->topology, session->pending_media_state->topology)) {
+               use_pending = 0;
+               use_active = 0;
+       }
+
+       if (use_pending) {
                pending_media_state = ast_sip_session_media_state_clone(session->pending_media_state);
                if (!pending_media_state) {
                        SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: Failed to clone pending media state\n", session_name);
                }
+       }
 
+       if (use_active) {
                active_media_state = ast_sip_session_media_state_clone(session->active_media_state);
                if (!active_media_state) {
                        ast_sip_session_media_state_free(pending_media_state);