tagdemux: resize and trim buffer in place to fix interaction with oggdemux
requested to merge tpm/gst-plugins-base:tagdemux-fix-buffer-trimming-with-oggdemux-pulling into master
Elements operating in pull mode may optionally pass a buffer to pull_range that should be filled with the data. The only element that does that at the moment is oggdemux operating in pull mode.
tagdemux currently creates a sub-buffer whenever a buffer pulled from upstream (filesrc, usually) needs to be trimmed. This creates a new buffer, however, so disregards any passed-in buffer from a downstream oggdemux.
This would cause assertion failures and playback problems for ogg files that contain ID3 tags at the end.
Fixes #848 (closed)