fix #442: non-pyobject for-in-loop targets failed with enumerate() optimisation

Cython/Compiler/Optimize.py

@@ -236,10 +236,6 @@ class IterationTransform(Visitor.VisitorTransform):
         if not counter_type.is_pyobject and not counter_type.is_int:
             # nothing we can do here, I guess
             return node
-        
-        if iterable_target.type is not PyrexTypes.py_object_type:
-            # this may need conversion, could be made to work
-            return node
 
         temp = UtilNodes.LetRefNode(ExprNodes.IntNode(enumerate_function.pos,
                                                       value='0',
@@ -276,6 +272,7 @@ class IterationTransform(Visitor.VisitorTransform):
                 stats = loop_body)
 
         node.target = iterable_target
+        node.item = node.item.coerce_to(iterable_target.type, self.current_scope)
         node.iterator.sequence = enumerate_function.arg_tuple.args[0]
 
         # recurse into loop to check for further optimisations

tests/run/enumerate_T316.pyx

@@ -12,7 +12,7 @@ def go_py_enumerate():
     for i,k in enumerate(range(1,5)):
         print i, k
 
-#T442 @cython.test_fail_if_path_exists("//SimpleCallNode//NameNode[@name = 'enumerate']")
+@cython.test_fail_if_path_exists("//SimpleCallNode//NameNode[@name = 'enumerate']")
 def go_c_enumerate():
     """
     >>> go_c_enumerate()
@@ -25,7 +25,7 @@ def go_c_enumerate():
     for i,k in enumerate(range(1,5)):
         print i, k
 
-#T442 @cython.test_fail_if_path_exists("//SimpleCallNode//NameNode[@name = 'enumerate']")
+@cython.test_fail_if_path_exists("//SimpleCallNode//NameNode[@name = 'enumerate']")
 def go_c_enumerate_step():
     """
     >>> go_c_enumerate_step()
@@ -97,7 +97,7 @@ def py_enumerate_continue(*t):
         continue
     print u"::", i, k
 
-# T442 @cython.test_fail_if_path_exists("//SimpleCallNode//NameNode[@name = 'enumerate']")
+@cython.test_fail_if_path_exists("//SimpleCallNode//NameNode[@name = 'enumerate']")
 def empty_c_enumerate():
     """
     >>> empty_c_enumerate()
@@ -132,7 +132,7 @@ def multi_enumerate():
     for a,(b,(c,d)) in enumerate(enumerate(enumerate(range(1,5)))):
         print a,b,c,d
 
-# T442 @cython.test_fail_if_path_exists("//SimpleCallNode")
+@cython.test_fail_if_path_exists("//SimpleCallNode")
 def multi_c_enumerate():
     """
     >>> multi_c_enumerate()
@@ -145,7 +145,7 @@ def multi_c_enumerate():
     for a,(b,(c,d)) in enumerate(enumerate(enumerate(range(1,5)))):
         print a,b,c,d
 
-# T442 @cython.test_fail_if_path_exists("//SimpleCallNode")
+@cython.test_fail_if_path_exists("//SimpleCallNode")
 def convert_target_enumerate(L):
     """
     >>> convert_target_enumerate([2,3,5])