cms-sw/cmssw — pull request #2716 by wmtan (2014-03-04 19:57:42+00:00)
Title: Avoid segfault in playback mode if no files specified

When running the mixing module in playback mode, if the secondary input source is given an empty file list, a segfault resulted when attempting to throw an exception. This pull request fixes the segfault so that the exception is thrown.
This pull request also improves exception messages that occur on an empty file list for the secondary source when playback mode is not used.