Ensure automatic cypclass write lock acquisition is not nested

Cython/Compiler/CypclassTransforms.py

@@ -446,11 +446,13 @@ class CypclassLockTransform(Visitor.EnvTransform):
             return obj
         except:
             self.autolocks += 1
+            self.autowlocks += exclusive
             return ExprNodes.CoerceToLockedNode(obj, self.current_env(), rlock_only = not exclusive)
 
     def __call__(self, root):
         self.locked = {}
         self.autolocks = 0
+        self.autowlocks = 0
         return super(CypclassLockTransform, self).__call__(root)
 
     def visit_Node(self, node):
@@ -503,24 +505,16 @@ class CypclassLockTransform(Visitor.EnvTransform):
         autolocks = self.autolocks
         node = self.visit(node)
         if self.autolocks > autolocks:
-            self.autolocks = 0
             return node.coerce_to_temp(self.current_env())
         return node
 
-    def visit_IndexNode(self, node):
-        node.index = self.visit_value(node.index)
-        node.base = self.visit(node.base)
-        return node
-
-    def visit_DelStatNode(self, node):
-        for arg in node.args:
-            arg_entry = self.id(arg)
-            if arg_entry in self.locked:
-                # Disallow unbinding a locked name
-                error(arg.pos, "Deleting a locked cypclass reference")
-                return node
-        self.visitchildren(node)
-        return node
+    def visit_assignment(self, node):
+        autowlocks = self.autowlocks
+        self.visitchildren(node, exclude=['rhs'])
+        if self.autowlocks > autowlocks:
+            node.rhs = self.visit_value(node.rhs)
+        else:
+            node.rhs = self.visit(node.rhs)
 
     def visit_SingleAssignmentNode(self, node):
         lhs = node.lhs
@@ -528,8 +522,7 @@ class CypclassLockTransform(Visitor.EnvTransform):
             # Disallow re-binding a locked name
             error(lhs.pos, "Assigning to a locked cypclass reference")
             return node
-        node.rhs = self.visit_value(node.rhs)
-        self.visitchildren(node, exclude=['rhs'])
+        self.visit_assignment(node)
         return node
 
     def visit_CascadedAssignmentNode(self, node):
@@ -538,8 +531,17 @@ class CypclassLockTransform(Visitor.EnvTransform):
                 # Disallow re-binding a locked name
                 error(lhs.pos, "Assigning to a locked cypclass reference")
                 return node
-        node.rhs = self.visit_value(node.rhs)
-        self.visitchildren(node, exclude=['rhs'])
+        self.visit_assignment(node)
+        return node
+
+    def visit_DelStatNode(self, node):
+        for arg in node.args:
+            arg_entry = self.id(arg)
+            if arg_entry in self.locked:
+                # Disallow unbinding a locked name
+                error(arg.pos, "Deleting a locked cypclass reference")
+                return node
+        self.visitchildren(node)
         return node
 
     def visit_WithTargetAssignmentStatNode(self, node):