Correct a theoretical bug in helpers.prune_split

attic/helpers.py

@@ -99,10 +99,11 @@ def prune_split(archives, pattern, n, skip=[]):
         items.setdefault(key, [])
         items[key].append(a)
     for key, values in sorted(items.items(), reverse=True):
-        if n and values[0] not in skip:
+        if n:
             values.sort(key=attrgetter('ts'), reverse=True)
-            keep.append(values[0])
-            n -= 1
+            if values[0] not in skip:
+                keep.append(values[0])
+                n -= 1
     return keep