queue: post error message when pausing task

If downstream returns error and upstream has already delivered
everything (including EOS) and will no longer be around to find
out that we paused (and why), post error message.  Fixes #589991.

diff --git a/plugins/elements/gstqueue.c b/plugins/elements/gstqueue.c
index 20380af..4200605 100644 (file)
--- a/plugins/elements/gstqueue.c
+++ b/plugins/elements/gstqueue.c
@@ -1159,11 +1159,24 @@ gst_queue_loop (GstPad * pad)
   /* ERRORS */
 out_flushing:
   {
+    gboolean eos = queue->eos;
+    GstFlowReturn ret = queue->srcresult;
+
     gst_pad_pause_task (queue->srcpad);
     GST_CAT_LOG_OBJECT (queue_dataflow, queue,
-        "pause task, reason:  %s", gst_flow_get_name (queue->srcresult));
+        "pause task, reason:  %s", gst_flow_get_name (ret));
     GST_QUEUE_SIGNAL_DEL (queue);
     GST_QUEUE_MUTEX_UNLOCK (queue);
+    /* let app know about us giving up if upstream is not expected to do so */
+    /* UNEXPECTED is already taken care of elsewhere */
+    if (eos && (GST_FLOW_IS_FATAL (ret) || ret == GST_FLOW_NOT_LINKED) &&
+        (ret != GST_FLOW_UNEXPECTED)) {
+      GST_ELEMENT_ERROR (queue, STREAM, FAILED,
+          (_("Internal data flow error.")),
+          ("streaming task paused, reason %s (%d)",
+              gst_flow_get_name (ret), ret));
+      gst_pad_push_event (queue->srcpad, gst_event_new_eos ());
+    }
     return;
   }
 }