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.
diff --git a/Modules/_sqlite/module.c b/Modules/_sqlite/module.c
index 72c3a7f..59406e1 100644
--- a/Modules/_sqlite/module.c
+++ b/Modules/_sqlite/module.c
@@ -434,7 +434,7 @@
PyDict_SetItemString(dict, "OptimizedUnicode", (PyObject*)&PyUnicode_Type);
/* Set integer constants */
- for (i = 0; _int_constants[i].constant_name != 0; i++) {
+ for (i = 0; _int_constants[i].constant_name != NULL; i++) {
tmp_obj = PyLong_FromLong(_int_constants[i].constant_value);
if (!tmp_obj) {
goto error;