+= assignments bug fix.

jedi/evaluate/__init__.py

@@ -164,7 +164,11 @@ class Evaluator(object):
                     t = self.eval_element(rhs)
                     left = precedence.calculate(self, left, operator, t)
                 types = left
-                del self.predefined_if_name_dict_dict[for_stmt]
+                if ordered:
+                    # If there are no for entries, we cannot iterate and the
+                    # types are defined by += entries. Therefore the for loop
+                    # is never called.
+                    del self.predefined_if_name_dict_dict[for_stmt]
             else:
                 types = precedence.calculate(self, left, operator, types)
         debug.dbg('eval_statement result %s', types)

jedi/evaluate/iterable.py

@@ -406,7 +406,6 @@ def ordered_elements_of_iterable(evaluator, iterable_type, all_values):
             ordered = [literals_to_types(evaluator, all_values)]
             break
         else:
-            # Try
             for i, types in enumerate(sequence.per_index_values()):
                 try:
                     ordered[i] |= types