Use NULL rather than 0. (#778)

There was few cases of using literal 0 instead of NULL in the context of
pointers.  While this was a legitimate C code, using NULL rather than 0 makes
the code clearer.

1 files changed, 1 insertions, 1 deletions

diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 9b368ca..0b6faf9 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -132,7 +132,7 @@ _ctypes_get_errobj(int **pspace)
     PyObject *dict = PyThreadState_GetDict();
     PyObject *errobj;
     static PyObject *error_object_name;
-    if (dict == 0) {
+    if (dict == NULL) {
         PyErr_SetString(PyExc_RuntimeError,
                         "cannot get thread state");
         return NULL;