Combine reverse and sort into one where possible

src/Products/ZCatalog/Catalog.py

@@ -655,9 +655,10 @@ class Catalog(Persistent, Acquisition.Implicit, ExtensionClass.Base):
                     append((k, intset, _self__getitem__))
                     # Note that sort keys are unique.
 
-            result.sort()
             if reverse:
-                result.reverse()
+                result.sort(reverse=True)
+            else:
+                result.sort()
             result = LazyCat(LazyValues(result), length)
         elif limit is None or (limit * 4 > rlen):
             # Iterate over the result set getting sort keys from the index
@@ -674,9 +675,10 @@ class Catalog(Persistent, Acquisition.Implicit, ExtensionClass.Base):
                     # results with those of other catalogs while avoiding
                     # the cost of instantiating a LazyMap per result
             if merge:
-                result.sort()
                 if reverse:
-                    result.reverse()
+                    result.sort(reverse=True)
+                else:
+                    result.sort()
                 if limit is not None:
                     result = result[:limit]
                 result = LazyValues(result)

src/Products/ZCatalog/tests/test_catalog.py

@@ -46,8 +46,11 @@ def createDatabase():
 app = createDatabase()
 
 
-def sort(iterable):
+def sort(iterable, reverse=False):
     L = list(iterable)
+    if reverse:
+        L.sort(reverse=True)
+    else:
         L.sort()
     return L
 
@@ -532,8 +535,7 @@ class TestMerge(CatalogBase, unittest.TestCase):
                    for cat in self.catalogs]
         merged_rids = [r.getRID() for r in mergeResults(
             results, has_sort_keys=True, reverse=True)]
-        expected = sort(chain(*results))
-        expected.reverse()
+        expected = sort(chain(*results), reverse=True)
         expected = [rid for sortkey, rid, getitem in expected]
         self.assertEqual(merged_rids, expected)