Fixes Issue 811 by detecting and failing early if getHybridRelease gets an empty fullreleaselist passed into it.

headphones/importer.py

@@ -251,7 +251,13 @@ def addArtisttoDB(artistid, extrasonly=False):
                 myDB.upsert("alltracks", newValueDict, controlValueDict)
 
         # Basically just do the same thing again for the hybrid release
-        hybridrelease = getHybridRelease(fullreleaselist)
+        # This may end up being called with an empty fullreleaselist
+        try:
+            hybridrelease = getHybridRelease(fullreleaselist)
+        except Exception, e:
+            errors = True
+            logger.warn('Unable to get hybrid release information for %s: %s' % (rg['title'],e))
+            continue
         
         # Use the ReleaseGroupID as the ReleaseID for the hybrid release to differentiate it
         # We can then use the condition WHERE ReleaseID == ReleaseGroupID to select it
@@ -584,6 +590,8 @@ def getHybridRelease(fullreleaselist):
     """
     Returns a dictionary of best group of tracks from the list of releases & earliest release date
     """
+    if len(fullreleaselist) == 0:
+        raise Exception("getHybridRelease was called with an empty fullreleaselist")
     sortable_release_list = []
         
     for release in fullreleaselist: