diff mbox series

[29/59] Simplify setting tz_rules to UTC

Message ID	20250105055750.1668721-30-eggert@cs.ucla.edu (mailing list archive)
State	New
Headers	DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1AE593858C32 From: Paul Eggert <eggert@cs.ucla.edu> To: libc-alpha@sourceware.org Cc: Paul Eggert <eggert@cs.ucla.edu> Subject: [PATCH 29/59] Simplify setting tz_rules to UTC Date: Sat, 4 Jan 2025 21:57:04 -0800 Message-ID: <20250105055750.1668721-30-eggert@cs.ucla.edu> In-Reply-To: <01207110-bd60-46ae-9c08-fb39c2011067@cs.ucla.edu> References: <01207110-bd60-46ae-9c08-fb39c2011067@cs.ucla.edu> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: list Errors-To: libc-alpha-bounces~patchwork=sourceware.org@sourceware.org
Series	time: sync mktime from Gnulib \| [00/59] time: sync mktime from Gnulib [01/59] Split intprops.h into two [02/59] Support stdckdint.h internally if older GCC [03/59] Fix mishandling of default DST rule [04/59] Don't worry about !TZDEFAULT [05/59] Support static_assert in pre-C23 C [06/59] Sync mktime.c from Gnulib 2024-10-04 [07/59] Document mktime out-of-range + tm_isdst [08/59] Push tzset lock into callers of time functions [09/59] Omit parse_offset unnecessary tz == '\0' [10/59] Don’t assume TZif bloat is likely [11/59] tzset no longer calls ftello [12/59] Check TZif files more carefully [13/59] Remove alignment assumption from __tzfile_read [14/59] Treat oddball UTC offset strings as zero [15/59] Simplify __tz_compute [16/59] Improve performance in 2 BC [17/59] Don’t mishandle years < 1970 in compute_change [18/59] Match RFC 9636 names [19/59] Trivial tzset_internal speedup [20/59] Fix obscure bug when stdoffset == dstoffset [21/59] Document assumption that NO_DST == 0 [22/59] __use_tzfile is boolean [23/59] Minor tzfile.c clarity improvements [24/59] Stop using zic's -y option [25/59] Fix mishandling of default DST rule [26/59] Simplify treatment of missing and empty TZ [27/59] TZ="" always means UTC sans leap seconds [28/59] Prefer "UTC" for UTC [29/59] Simplify setting tz_rules to UTC [30/59] Update tzname etc. even if TZ is unchanged [31/59] "POSIX TZ" -> "proleptic TZ" [32/59] Reject invalid TZ strings in TZif files [33/59] Reject TZif files containing '\0' in TZ string [34/59] mktime should not consult 'daylight' [35/59] Remove __use_tzfile [36/59] Remove arbitrary limit on TZ, TZDIR lengths [37/59] Tighten setuid TZif file name check [38/59] Avoid a malloc in __tzfile_read [39/59] Free earlier in __tzfile_read [40/59] Improve __tzfile_read TZ="" comment [41/59] Refactor enum tz_rule_type [42/59] __offtime now returns struct tm [43/59] Fix overflow checking in offtime [44/59] Handle TZif time type 0 correctly [45/59] Remove invalid tzset tests from tst-bz29951.c [46/59] tzset, not localtime, now parses TZif TZ spec [47/59] Minor compute_change widening tweak [48/59] Minor SECSPERDAY widening tweak [49/59] Remove leap-second goto from __tzfile_compute [50/59] Remove use_last label from __tzfile_compute [51/59] Refactor ‘if’ in __tzfile_compute [52/59] Refactor localtime ‘if’ in __tzfile_compute [53/59] Refactor post-transition-table ‘if’ [54/59] Refactor __tzfile_compute to avoid two gotos [55/59] Refactor __tzfile_compute index local [56/59] mktime: prefer bool to int [57/59] mktime: port __mktime64 locking to Gnulib [58/59] mktime: improve tm_isdst heuristic [59/59] time: test DST adjustment for DST-less zones

Checks

Context	Check	Description
redhat-pt-bot/TryBot-apply_patch	success	Patch applied to master at the time it was sent

Commit Message

Paul Eggert Jan. 5, 2025, 5:57 a.m. UTC

  * time/tzset.c (__tzset_parse_tz): Reset to named UTC, not unnamed.
(tzset_internal): Rely on __tzset_parse_tz to reset state.
---
 time/tzset.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff mbox series

Patch

diff --git a/time/tzset.c b/time/tzset.c
index 2bbf8f055b..1873ad205b 100644
--- a/time/tzset.c
+++ b/time/tzset.c
@@ -352,11 +352,11 @@  parse_rule (const char **tzp, int whichrule)
 void
 __tzset_parse_tz (const char *tz)
 {
-  /* Clear out old state and reset to unnamed UTC.  */
+  /* Clear out old state and reset to UTC.  */
   memset (tz_rules, '\0', sizeof tz_rules);
   if (NO_DST != 0)
     tz_rules[0].type = tz_rules[1].type = NO_DST;
-  tz_rules[0].name = tz_rules[1].name = "";
+  tz_rules[0].name = tz_rules[1].name = "UTC";
 
   /* Get the standard time zone abbreviations.  */
   if (parse_tzname (&tz, 0) && parse_offset (&tz, 0))
@@ -410,9 +410,6 @@  tzset_internal (int always)
     /* No change, simply return.  */
     return;
 
-  tz_rules[0].name = NULL;
-  tz_rules[1].name = NULL;
-
   /* Save the value of `tz'.  */
   free (old_tz);
   old_tz = __strdup (tz);
@@ -422,18 +419,10 @@  tzset_internal (int always)
   if (__use_tzfile)
     return;
 
-  /* No data file found.  Default to UTC if nothing specified or if
+  /* No data file found.  Default to UTC without leap seconds if
      TZDEFAULT is broken.  */
-
-  if (*tz == '\0' || strcmp (tz, TZDEFAULT) == 0)
-    {
-      memset (tz_rules, '\0', sizeof tz_rules);
-      tz_rules[0].name = tz_rules[1].name = "UTC";
-      if (NO_DST != 0)
-	tz_rules[0].type = tz_rules[1].type = NO_DST;
-      update_vars ();
-      return;
-    }
+  if (strcmp (tz, TZDEFAULT) == 0)
+    tz = "";
 
   __tzset_parse_tz (tz);
 }