Calls to the playlist function with a specific action fail

If the swf() function is called with a specific action set and a playlist then the proper flag isn't set on the call to swftools_prepare_playlist() to indicate that an action has already been given. The playlist function therefore tries to assign an action in every case.

When the content includes streams or references to urls that don't have a file extension then the action assignment fails and an empty playlist can be returned.