Fix for SF# 1649098: avoid zero-sized array declaration in structure.

Modules/_ctypes/callbacks.c

@@ -268,7 +268,7 @@ ffi_info *AllocFunctionCallback(PyObject *callable,
 	ffi_abi cc;
 
 	nArgs = PySequence_Size(converters);
-	p = (ffi_info *)PyMem_Malloc(sizeof(ffi_info) + sizeof(ffi_type) * (nArgs + 1));
+	p = (ffi_info *)PyMem_Malloc(sizeof(ffi_info) + sizeof(ffi_type) * (nArgs));
 	if (p == NULL) {
 		PyErr_NoMemory();
 		return NULL;

Modules/_ctypes/ctypes.h

@@ -74,7 +74,7 @@ typedef struct {
 	PyObject *callable;
 	SETFUNC setfunc;
 	ffi_type *restype;
-	ffi_type *atypes[0];
+	ffi_type *atypes[1];
 } ffi_info;
 
 typedef struct {