ext/ogg/gstoggdemux.c: Check for pad availability before using it.
ext/ogg/gstoggdemux.c: Check for pad availability before using it.

Original commit message from CVS:
* ext/ogg/gstoggdemux.c: (gst_ogg_demux_src_query),
(gst_ogg_demux_src_event), (_find_chain_seek),
(gst_ogg_pad_push):
Check for pad availability before using it.
* ext/ogg/gstoggdemux.c: (_find_chain_process):
Fix parsing of chained ogg. Needs more work on the decoder side.

jar1karp/gst-plugins-ugly,matsu/gst-plugins-ugly,surround-io/gst-plugins-ugly,shelsonjava/gst-plugins-ugly,ahmedammar/platform_external_gst_plugins_ugly,GStreamer/gst-plugins-ugly,collects/gst-plugins-ugly,ylatuya/gst-plugins-ugly,knuesel/gst-plugins-ugly,jahrome/gst-plugins-ugly,sebras/gst-plugins-ugly,krieger-od/gst-plugins-ugly,Distrotech/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,knuesel/gst-plugins-ugly,GStreamer/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,jpakkane/gstreamer-plugins-ugly,krieger-od/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,reynaldo-samsung/gst-plugins-ugly,reynaldo-samsung/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,prajnashi/gst-plugins-ugly,matsu/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,knuesel/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer__gst-plugins-ugly,matsu/gst-plugins-ugly,ahmedammar/platform_external_gst_plugins_ugly,jahrome/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer-sdk__gst-plugins-ugly,ylatuya/gst-plugins-ugly,alessandrod/gst-plugins-ugly,GStreamer/gst-plugins-ugly,Kurento/gst-plugins-ugly,jahrome/gst-plugins-ugly,Lachann/gst-plugins-ugly,fluendo/gst-plugins-ugly,krieger-od/gst-plugins-ugly,PPCDroid/external-gst-plugins-ugly,Kurento/gst-plugins-ugly,Lachann/gst-plugins-ugly,Kurento/gst-plugins-ugly,Distrotech/gst-plugins-ugly,Distrotech/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer-sdk__gst-plugins-ugly,shelsonjava/gst-plugins-ugly,shelsonjava/gst-plugins-ugly,prajnashi/gst-plugins-ugly,Distrotech/gst-plugins-ugly,reynaldo-samsung/gst-plugins-ugly,prajnashi/gst-plugins-ugly,fluendo/gst-plugins-ugly,jar1karp/gst-plugins-ugly,PPCDroid/external-gst-plugins-ugly,collects/gst-plugins-ugly,jpakkane/gstreamer-plugins-ugly,collects/gst-plugins-ugly,sebras/gst-plugins-ugly,collects/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer__gst-plugins-ugly,jpakkane/gstreamer-plugins-ugly,alessandrod/gst-plugins-ugly,sebras/gst-plugins-ugly,PPCDroid/external-gst-plugins-ugly,StreamUtils/gst-plugins-ugly,ahmedammar/platform_external_gst_plugins_ugly,cablelabs/gst-plugins-ugly,krieger-od/gst-plugins-ugly,cablelabs/gst-plugins-ugly,matsu/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer-sdk__gst-plugins-ugly,Lachann/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer__gst-plugins-ugly,surround-io/gst-plugins-ugly,alessandrod/gst-plugins-ugly,jar1karp/gst-plugins-ugly,Distrotech/gst-plugins-ugly,ylatuya/gst-plugins-ugly,surround-io/gst-plugins-ugly,cablelabs/gst-plugins-ugly,fluendo/gst-plugins-ugly