hwclock: remove UTC-0 localization hack

Use timegm(3) instead rather than re-implement same functionality with
mktime(3) combined with removal of TZ localization.

Reviewed-by: J William Piggott <elseifthen@gmx.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/sys-utils/hwclock.c b/sys-utils/hwclock.c
index 10d9e37e995e3ef917c670b0513df7af56c107c0..1d193a5dac218dcaa8535d8e592a5206f8c4a7e5 100644 (file)
--- a/sys-utils/hwclock.c
+++ b/sys-utils/hwclock.c
@@ -389,27 +389,11 @@ static void
 mktime_tz(struct tm tm, const bool universal,
          bool * valid_p, time_t * systime_p)
 {
-       time_t mktime_result;   /* The value returned by our mktime() call */
-       char *zone;             /* Local time zone name */
-
-       /*
-        * We use the C library function mktime(), but since it only works
-        * on local time zone input, we may have to fake it out by
-        * temporarily changing the local time zone to UTC.
-        */
-       zone = getenv("TZ");    /* remember original time zone */
-       if (universal) {
-               /* Set timezone to UTC */
-               xsetenv("TZ", "", TRUE);
-               /*
-                * Note: tzset() gets called implicitly by the time code,
-                * but only the first time. When changing the environment
-                * variable, better call tzset() explicitly.
-                */
-               tzset();
-       }
-       mktime_result = mktime(&tm);
-       if (mktime_result == -1) {
+       if (universal)
+               *systime_p = timegm(&tm);
+       else
+               *systime_p = mktime(&tm);
+       if (*systime_p == -1) {
                /*
                 * This apparently (not specified in mktime() documentation)
                 * means the 'tm' structure does not contain valid values
@@ -417,7 +401,6 @@ mktime_tz(struct tm tm, const bool universal,
                 * mktime() returns -1).
                 */
                *valid_p = FALSE;
-               *systime_p = 0;
                if (debug)
                        printf(_("Invalid values in hardware clock: "
                                 "%4d/%.2d/%.2d %.2d:%.2d:%.2d\n"),
@@ -425,7 +408,6 @@ mktime_tz(struct tm tm, const bool universal,
                               tm.tm_hour, tm.tm_min, tm.tm_sec);
        } else {
                *valid_p = TRUE;
-               *systime_p = mktime_result;
                if (debug)
                        printf(_
                               ("Hw clock time : %4d/%.2d/%.2d %.2d:%.2d:%.2d = "
@@ -433,12 +415,6 @@ mktime_tz(struct tm tm, const bool universal,
                               tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min,
                               tm.tm_sec, (long)*systime_p);
        }
-       /* now put back the original zone. */
-       if (zone)
-               xsetenv("TZ", zone, TRUE);
-       else
-               unsetenv("TZ");
-       tzset();
 }
 
 /*