replaygain: Check for bad mp3gain output (#961)

beetsplug/replaygain.py

@@ -198,6 +198,9 @@ class CommandBackend(Backend):
         out = []
         for line in text.split('\n')[1:num_lines + 1]:
             parts = line.split('\t')
+            if len(parts) != 6 or parts[0] == 'File':
+                log.debug(u'replaygain: bad tool output: {0}'.format(text))
+                raise ReplayGainError('mp3gain failed')
             d = {
                 'file': parts[0],
                 'mp3gain': int(parts[1]),

docs/changelog.rst

@@ -62,6 +62,9 @@ Fixes:
   whitelist. Thanks to gwern.
 * :doc:`/plugins/importfeeds`: A new ``echo`` output mode prints files' paths
   to standard error. Thanks to robotanarchy.
+* :doc:`/plugins/replaygain`: Restore some error handling when ``mp3gain``
+  output cannot be parsed. The verbose log now contains the bad tool output in
+  this case.
 
 .. _discogs_client: https://github.com/discogs/discogs_client