Hash collision security issue

Modules/datetimemodule.c

 /*  C implementation for the date/time type documented at
  *  http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage
  */
 
 #include "Python.h"
 #include "modsupport.h"
 #include "structmember.h"
 
 #include <time.h>
 
@@ skipping 2548 matching lines @@
 /*
     Borrowed from stringobject.c, originally it was string_hash()
 */
 static long
 generic_hash(unsigned char *data, int len)
 {
     register unsigned char *p;
     register long x;
 
     p = (unsigned char *) data;
-    x = *p << 7;
+    x = _Py_HashSecret.prefix;
+    x ^= *p << 7;
     while (--len >= 0)
         x = (1000003*x) ^ *p++;
     x ^= len;
+    x ^= _Py_HashSecret.suffix;
     if (x == -1)
         x = -2;
 
     return x;
 }
 
 
 static PyObject *date_getstate(PyDateTime_Date *self);
 
 static long
@@ skipping 2441 matching lines @@
    enough to say.
 
 In any case, it's clear that the default fromutc() is strong enough to handle
 "almost all" time zones:  so long as the standard offset is invariant, it
 doesn't matter if daylight time transition points change from year to year, or
 if daylight time is skipped in some years; it doesn't matter how large or
 small dst() may get within its bounds; and it doesn't even matter if some
 perverse time zone returns a negative dst()).  So a breaking case must be
 pretty bizarre, and a tzinfo subclass can override fromutc() if it is.
 --------------------------------------------------------------------------- */