improve logging, fix potential use of already freed pointer

src/belle_sip_object.c

@@ -67,7 +67,12 @@ belle_sip_object_t * belle_sip_object_ref(void *obj){
 
 void belle_sip_object_unref(void *ptr){
 	belle_sip_object_t *obj=BELLE_SIP_OBJECT(ptr);
-	if (obj->ref==-1) belle_sip_fatal("Object with name [%s] freed twice !",obj->name);
+	if (obj->ref==-1) {
+		belle_sip_error("Object [%p] freed twice !",obj);
+		if (obj->vptr && obj->vptr->type_name) belle_sip_error("Object type might be [%s]",obj->vptr->type_name);
+		belle_sip_fatal("Fatal object error encountered, aborting.");
+		return;
+	}
 	if (obj->ref==0 && obj->pool){
 		belle_sip_object_pool_remove(obj->pool,obj);
 		obj->ref=-1;

src/message.c

@@ -300,10 +300,8 @@ void belle_sip_request_set_dialog(belle_sip_request_t *req, belle_sip_dialog_t *
 	if (dialog) belle_sip_object_ref(dialog);
 	if (req->dialog) {
 		belle_sip_object_unref(req->dialog);
-		req->dialog=NULL;
 	}
 	req->dialog=dialog;
-	
 }
 
 void belle_sip_request_set_uri(belle_sip_request_t* request,belle_sip_uri_t* uri) {

src/transaction.c

@@ -111,13 +111,12 @@ void belle_sip_transaction_terminate(belle_sip_transaction_t *t){
 									,belle_sip_request_get_method(belle_sip_transaction_get_request(t))
 									,t);
 		BELLE_SIP_OBJECT_VPTR(t,belle_sip_transaction_t)->on_terminate(t);
-		belle_sip_provider_set_transaction_terminated(t->provider,t);
-		
 		/*remove reference to the dialog to avoid circular references*/
 		if (t->dialog){
 			belle_sip_object_unref(t->dialog);
 			t->dialog=NULL;
 		}
+		belle_sip_provider_set_transaction_terminated(t->provider,t);
 	}
 }