Catch time(), ftime(), localtime() and clock() errors

Modules/_datetimemodule.c

 /*  C implementation for the date/time type documented at
  *  http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage
  */
 
 #include "Python.h"
 #include "structmember.h"
 
 #include <time.h>
 
 #include "_time.h"
@@ skipping 4114 matching lines @@
 }
 
 /* Internal helper.
  * Build most accurate possible datetime for current time.  Pass localtime or
  * gmtime for f as appropriate.
  */
 static PyObject *
 datetime_best_possible(PyObject *cls, TM_FUNC f, PyObject *tzinfo)
 {
     _PyTime_timeval t;
-    _PyTime_gettimeofday(&t);
+    if (_PyTime_gettimeofday(&t) == -1)
+        return NULL;
     return datetime_from_timet_and_us(cls, f, t.tv_sec, (int)t.tv_usec,
                                       tzinfo);
 }
 
 /* Return best possible local time -- this isn't constrained by the
  * precision of a timestamp.
  */
 static PyObject *
 datetime_now(PyObject *cls, PyObject *args, PyObject *kw)
 {
@@ skipping 1277 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.
 --------------------------------------------------------------------------- */