prevent dict iter optimisation from striking at methods with unusual number of arguments

Cython/Compiler/Optimize.py

@@ -164,9 +164,16 @@ class IterationTransform(Visitor.VisitorTransform):
         if not isinstance(iterator, ExprNodes.SimpleCallNode):
             return node
 
+        if iterator.args is None:
+            arg_count = iterator.arg_tuple and len(iterator.arg_tuple.args) or 0
+        else:
+            arg_count = len(iterator.args)
+            if arg_count and iterator.self is not None:
+                arg_count -= 1
+
         function = iterator.function
         # dict iteration?
-        if function.is_attribute and not reversed:
+        if function.is_attribute and not reversed and not arg_count:
             base_obj = iterator.self or function.obj
             method = function.attribute
 

tests/run/iterdict.pyx

@@ -174,6 +174,17 @@ def iterkeys(dict d):
     l.sort()
     return l
 
+@cython.test_fail_if_path_exists(
+    "//WhileStatNode",
+    "//WhileStatNode//DictIterationNextNode")
+def iterkeys_argerror(dict d):
+    """
+    >>> try: iterkeys_argerror(d)
+    ... except TypeError: pass
+    """
+    for k in d.iterkeys(1):
+        print k
+
 @cython.test_assert_path_exists(
     "//WhileStatNode",
     "//WhileStatNode//DictIterationNextNode")
@@ -203,6 +214,17 @@ def optimistic_iterkeys(d):
     l.sort()
     return l
 
+@cython.test_fail_if_path_exists(
+    "//WhileStatNode",
+    "//WhileStatNode//DictIterationNextNode")
+def optimistic_iterkeys_argerror(d):
+    """
+    >>> try: optimistic_iterkeys_argerror(d)
+    ... except TypeError: pass
+    """
+    for k in d.iterkeys(1):
+        print k
+
 @cython.test_assert_path_exists(
     "//WhileStatNode",
     "//WhileStatNode//DictIterationNextNode")