fixed handling of misnumbered tracks during ordering

beets/autotag/__init__.py

@@ -130,12 +130,17 @@ def _order_items_meta(items):
     for item in items:
         if item.track:
             index = item.track - 1
-            ordered_items[index] = item
+            
+            # Make sure the index is valid.
             if index in available_indices:
                 available_indices.remove(index)
             else:
                 # Same index used twice.
                 return None
+                
+            # Apply index.
+            ordered_items[index] = item
+            
         else:
             # If we have any item without an index, give up.
             return None
@@ -144,6 +149,8 @@ def _order_items_meta(items):
         # Not all indices were used.
         return None
     
+    return ordered_items
+
 def _order_items_match(items, trackinfo):
     """Orders the items based on how they match some canonical track
     information. This always produces a result if the numbers of tracks

test/test_autotag.py

@@ -193,6 +193,34 @@ class AlbumsInDirTest(unittest.TestCase):
             else:
                 self.assertEqual(len(album), 1)
 
+class OrderingTest(unittest.TestCase):
+    def test_metaorder_fails_on_duplicated_tracknum(self):
+        items = []
+        items.append(Item({'title': 'two', 'track': 2}))
+        items.append(Item({'title': 'one', 'track': 1}))
+        items.append(Item({'title': 'twoagain', 'track': 2}))
+        ordered = autotag._order_items_meta(items)
+        self.assertEqual(ordered, None)
+    
+    def test_metaorder_fails_on_too_high_tracknum(self):
+        items = []
+        items.append(Item({'title': 'four', 'track': 4}))
+        items.append(Item({'title': 'one', 'track': 1}))
+        items.append(Item({'title': 'two', 'track': 2}))
+        ordered = autotag._order_items_meta(items)
+        self.assertEqual(ordered, None)
+        
+    def test_metaorder_correct(self):
+        items = []
+        items.append(Item({'title': 'three', 'track': 3}))
+        items.append(Item({'title': 'one', 'track': 1}))
+        items.append(Item({'title': 'two', 'track': 2}))
+        ordered = autotag._order_items_meta(items)
+        self.assertEqual(ordered[0].title, 'one')
+        self.assertEqual(ordered[1].title, 'two')
+        self.assertEqual(ordered[2].title, 'three')
+    
+
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)