casting to typedef pointer/array types (ticket #518)

Cython/Compiler/PyrexTypes.py

@@ -228,8 +228,9 @@ class CTypedefType(BaseType):
     def cast_code(self, expr_code):
         # If self is really an array (rather than pointer), we can't cast.
         # For example, the gmp mpz_t. 
-        if self.typedef_base_type.is_ptr:
-            return self.typedef_base_type.cast_code(expr_code)
+        if self.typedef_base_type.is_array:
+            base_type = self.typedef_base_type.base_type
+            return CPtrType(base_type).cast_code(expr_code)
         else:
             return BaseType.cast_code(self, expr_code)
 

tests/compile/cast_ctypedef_array_T518.pyx

+cdef extern from "cast_ctypedef_array_T518_helper.h":
+    cdef struct __foo_struct:
+       int i, j
+    ctypedef __foo_struct foo_t[1]
+
+    void foo_init(foo_t)
+    void foo_clear(foo_t)
+
+cdef foo_t value
+foo_init(value) 
+foo_clear(value) 
+
+cdef void *pointer = <void*> value
+foo_init(<foo_t>pointer) 
+foo_clear(<foo_t>pointer) 

tests/compile/cast_ctypedef_array_T518_helper.h

+struct __foo_struct { int i, j; };
+typedef struct __foo_struct foo_t[1];
+
+static void foo_init  (foo_t v) { v[0].i = 0; v[0].j = 0; }
+static void foo_clear (foo_t v) { v[0].i = 0; v[0].j = 0; }