Ignore comments when determine what's a dict maker.

CHANGELOG

@@ -9,6 +9,7 @@
 - Retain proper vertical spacing before comments in a data literal.
 - Make sure that continuations from a compound statement are distinguished from
   the succeeding line.
+- Ignore preceding comments when calculating what is a "dictonary maker".
 
 ## [0.6.0] 2015-10-18
 ### Added

yapf/yapflib/subtype_assigner.py

@@ -62,9 +62,16 @@ def Visit_dictsetmaker(self, node):  # pylint: disable=invalid-name
     # dictsetmaker ::= (test ':' test (comp_for |
     #                                   (',' test ':' test)* [','])) |
     #                  (test (comp_for | (',' test)* [',']))
-    dict_maker = (len(node.children) > 1 and isinstance(node.children[1],
-                                                        pytree.Leaf) and
-                  node.children[1].value == ':')
+    dict_maker = False
+    if len(node.children) > 1:
+      index = 0
+      while index < len(node.children):
+        if pytree_utils.NodeName(node.children[index]) != 'COMMENT':
+          break
+        index += 1
+      if index < len(node.children):
+        child = node.children[index + 1]
+        dict_maker = isinstance(child, pytree.Leaf) and child.value == ':'
     last_was_comma = False
     last_was_colon = False
     for child in node.children:

yapftests/reformatter_test.py

@@ -1477,6 +1477,26 @@ class BuganizerFixes(ReformatterTest):
   def setUpClass(cls):
     style.SetGlobalStyle(style.CreateChromiumStyle())
 
+  def testB25136820(self):
+    unformatted_code = textwrap.dedent("""\
+        def foo():
+          return collections.OrderedDict({
+              # Preceding comment.
+              'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa':
+              '$bbbbbbbbbbbbbbbbbbbbbbbb',
+          })
+        """)
+    expected_formatted_code = textwrap.dedent("""\
+        def foo():
+          return collections.OrderedDict({
+              # Preceding comment.
+              'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa':
+                  '$bbbbbbbbbbbbbbbbbbbbbbbb',
+          })
+        """)
+    uwlines = _ParseAndUnwrap(unformatted_code)
+    self.assertCodeEqual(expected_formatted_code, reformatter.Reformat(uwlines))
+
   def testB25131481(self):
     unformatted_code = textwrap.dedent("""\
         APPARENT_ACTIONS = ('command_type', {