problem about zdump

["Wanghui (John)" <john dot wanghui at huawei dot com>]

Distribution
CentOS 7.1

Version
glibc-2.17-106

zdump -v Africa/Casablanca | grep 2037
after excute the command above, it shows:

Africa/Casablanca  Sun Mar 29 01:59:59 2037 UTC = Sun Mar 29 01:59:59 2037 WET isdst=0 gmtoff=0
Africa/Casablanca  Sun Mar 29 02:00:00 2037 UTC = Sun Mar 29 03:00:00 2037 WEST isdst=1 gmtoff=3600
Africa/Casablanca  Sun Oct 25 01:59:59 2037 UTC = Sun Oct 25 02:59:59 2037 WEST isdst=1 gmtoff=3600
Africa/Casablanca  Sun Oct 25 02:00:00 2037 UTC = Sun Oct 25 02:00:00 2037 WET isdst=0 gmtoff=0

But in tzdata:
Rule    Morocco 2035    only    -       Oct     27       3:00   0       -
Rule    Morocco 2036    only    -       Oct     18       3:00   0       -
Rule    Morocco 2037    only    -       Oct     10       3:00   0       -

So daylight saving time should be Oct 10th 2037 in Casablanca according to the tzfile

it might be because of thisï
      else if (__builtin_expect (timer >= transitions[num_transitions - 1], 0))
	{
	  if (__builtin_expect (tzspec == NULL, 0))
	    {
	    use_last:
	      i = num_transitions;
	      goto found;
	    }

	  /* Parse the POSIX TZ-style string.  */
	  __tzset_parse_tz (tzspec);

	  /* Convert to broken down structure.  If this fails do not
	     use the string.  */
	  if (__builtin_expect (! __offtime (&timer, 0, tp), 0))
	    goto use_last;

	  /* Use the rules from the TZ string to compute the change.  */
	  __tz_compute (timer, tp, 1);

after 2037-10-10 is out of the range of the setting in tzdata file, so it recalculated the daylight saving time
with previous rules, and the result become 2037-10-25

Thanks