Add code to negotiation code that checks for empty caps

In that case, fail with NOT_NEGOTIATED

1 files changed, 6 insertions, 1 deletions

diff --git a/gst-libs/gst/cairo/gstcairopad.c b/gst-libs/gst/cairo/gstcairopad.c
index 5726a14..388c9b6 100644
--- a/gst-libs/gst/cairo/gstcairopad.c
+++ b/gst-libs/gst/cairo/gstcairopad.c
@@ -117,9 +117,14 @@ gst_cairo_pad_alloc_buffer_full (GstPad * pad,
   } else {
     caps = gst_pad_get_allowed_caps (pad);
 
-    if (caps && restrict_func)
+    if (caps && !gst_caps_is_empty (caps) && restrict_func)
       caps = restrict_func (caps, restrict_data);
 
+    if (gst_caps_is_empty (caps)) {
+      gst_caps_unref (caps);
+      return GST_FLOW_NOT_NEGOTIATED;
+    }
+
     if (caps == NULL)
       return GST_FLOW_NOT_NEGOTIATED;