1  /* Check that daylight is set if the last DST transition did not change offset.
       2     Copyright (C) 2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <stdlib.h>
      21  #include <support/check.h>
      22  #include <time.h>
      23  
      24  /* Set the specified time zone with error checking.  */
      25  static void
      26  set_timezone (const char *name)
      27  {
      28    TEST_VERIFY (setenv ("TZ", name, 1) == 0);
      29    errno = 0;
      30    tzset ();
      31    TEST_COMPARE (errno, 0);
      32  }
      33  
      34  static int
      35  do_test (void)
      36  {
      37    /* Test zone based on tz-2022g version of Africa/Tripoli.  The last
      38       DST transition coincided with a change in the standard time
      39       offset, effectively making it a no-op.
      40  
      41       Africa/Tripoli  Thu Oct 24 23:59:59 2013 UT
      42         = Fri Oct 25 01:59:59 2013 CEST isdst=1 gmtoff=7200
      43       Africa/Tripoli  Fri Oct 25 00:00:00 2013 UT
      44         = Fri Oct 25 02:00:00 2013 EET isdst=0 gmtoff=7200
      45     */
      46    set_timezone ("XT6");
      47    TEST_VERIFY (daylight != 0);
      48    TEST_COMPARE (timezone, -7200);
      49  
      50    /* Check that localtime re-initializes the two variables.  */
      51    daylight = timezone = 17;
      52    time_t t = 844034401;
      53    struct tm *tm = localtime (&t);
      54    TEST_VERIFY (daylight != 0);
      55    TEST_COMPARE (timezone, -7200);
      56    TEST_COMPARE (tm->tm_year, 96);
      57    TEST_COMPARE (tm->tm_mon, 8);
      58    TEST_COMPARE (tm->tm_mday, 29);
      59    TEST_COMPARE (tm->tm_hour, 23);
      60    TEST_COMPARE (tm->tm_min, 0);
      61    TEST_COMPARE (tm->tm_sec, 1);
      62    TEST_COMPARE (tm->tm_gmtoff, 3600);
      63    TEST_COMPARE (tm->tm_isdst, 0);
      64  
      65    return 0;
      66  }
      67  
      68  #include <support/test-driver.c>