Add 3 more bytes to a buffer to cover constants in string and null byte on top...

Add 3 more bytes to a buffer to cover constants in string and null byte on top of 10 possible digits for an int.

Closes bug #1501223.

Python/sysmodule.c

@@ -1031,7 +1031,7 @@ _PySys_Init(void)
 	PyObject *sysin, *sysout, *syserr;
 	char *s;
 #ifdef MS_WINDOWS
-	char buf[10];
+	char buf[13];
 #endif
 
 	m = Py_InitModule3("sys", sys_methods, sys_doc);