From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2178) id 9658F3858431; Tue, 10 Jan 2023 16:32:56 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9658F3858431 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1673368376; bh=vUB5wkBxvG2rbNd0vjp928/7Uvj5iPU2V+KwocczJOc=; h=From:To:Subject:Date:From; b=xgq/mFCYVI5hYlW98BTaYqHqc2hgEj0lYrIE61mCiOlmDzNpKuieHd7mjlXxTFdB0 mDXNJ2U+7LcHHqrDR4GNsF8B7kGZRnZsCK35lLTSpWyLaxYPYEcfE/t4hdxz0SZplv p0Z+0FxxMQm0KzDJx4dGS3+Ai6iQxhWaySEH/q3Y= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Florian Weimer To: glibc-cvs@sourceware.org Subject: [glibc/release/2.35/master] time: Set daylight to 1 for matching DST/offset change (bug 29951) X-Act-Checkin: glibc X-Git-Author: Florian Weimer X-Git-Refname: refs/heads/release/2.35/master X-Git-Oldrev: d9923235f012cdaeb3dff097e11660b7f5e5b00a X-Git-Newrev: 82663d3c034cd5d0d7efa2e92c380ced1ddbb09e Message-Id: <20230110163256.9658F3858431@sourceware.org> Date: Tue, 10 Jan 2023 16:32:56 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=82663d3c034cd5d0d7efa2e92c380ced1ddbb09e commit 82663d3c034cd5d0d7efa2e92c380ced1ddbb09e Author: Florian Weimer Date: Thu Jan 5 18:21:25 2023 +0100 time: Set daylight to 1 for matching DST/offset change (bug 29951) The daylight variable is supposed to be set to 1 if DST is ever in use for the current time zone. But __tzfile_read used to do this: __daylight = rule_stdoff != rule_dstoff; This check can fail to set __daylight to 1 if the DST and non-DST offsets happen to be the same. (cherry picked from commit 35141f304e319109c322f797ae71c0b9420ccb05) Diff: --- NEWS | 1 + time/tzfile.c | 41 +++++++++++++++-------------- timezone/Makefile | 4 ++- timezone/testdata/XT6 | Bin 0 -> 625 bytes timezone/tst-bz29951.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 94 insertions(+), 20 deletions(-) diff --git a/NEWS b/NEWS index 539ff38bb0..1beb3c6a82 100644 --- a/NEWS +++ b/NEWS @@ -70,6 +70,7 @@ The following bugs are resolved with this release: [29730] broken y2038 support in fstatat on MIPS N64 [29771] Restore IPC_64 support in sysvipc *ctl functions [29776] elf/tst-tlsopt-powerpc fails when compiled with -mcpu=power10 + [29951] time: Set daylight to 1 for matching DST/offset change Version 2.35 diff --git a/time/tzfile.c b/time/tzfile.c index 394b098856..8bba4e5b8d 100644 --- a/time/tzfile.c +++ b/time/tzfile.c @@ -61,6 +61,10 @@ static size_t num_leaps; static struct leap *leaps; static char *tzspec; +/* Used to restore the daylight variable during time conversion, as if + tzset had been called. */ +static int daylight_saved; + #include #include @@ -438,36 +442,35 @@ __tzfile_read (const char *file, size_t extra, char **extrap) if (__tzname[1] == NULL) __tzname[1] = __tzname[0]; + daylight_saved = 0; if (num_transitions == 0) /* Use the first rule (which should also be the only one). */ rule_stdoff = rule_dstoff = types[0].offset; else { - int stdoff_set = 0, dstoff_set = 0; - rule_stdoff = rule_dstoff = 0; + rule_stdoff = 0; + + /* Search for the last rule with a standard time offset. This + will be used for the global timezone variable. */ i = num_transitions - 1; do - { - if (!stdoff_set && !types[type_idxs[i]].isdst) - { - stdoff_set = 1; - rule_stdoff = types[type_idxs[i]].offset; - } - else if (!dstoff_set && types[type_idxs[i]].isdst) - { - dstoff_set = 1; - rule_dstoff = types[type_idxs[i]].offset; - } - if (stdoff_set && dstoff_set) + if (!types[type_idxs[i]].isdst) + { + rule_stdoff = types[type_idxs[i]].offset; break; - } + } + else + daylight_saved = 1; while (i-- > 0); - if (!dstoff_set) - rule_dstoff = rule_stdoff; + /* Keep searching to see if there is a DST rule. This + information will be used to set the global daylight + variable. */ + while (i-- > 0 && !daylight_saved) + daylight_saved = types[type_idxs[i]].isdst; } - __daylight = rule_stdoff != rule_dstoff; + __daylight = daylight_saved; __timezone = -rule_stdoff; done: @@ -731,7 +734,7 @@ __tzfile_compute (__time64_t timer, int use_localtime, } struct ttinfo *info = &types[i]; - __daylight = rule_stdoff != rule_dstoff; + __daylight = daylight_saved; __timezone = -rule_stdoff; if (__tzname[0] == NULL) diff --git a/timezone/Makefile b/timezone/Makefile index a789c22d26..5002de39ad 100644 --- a/timezone/Makefile +++ b/timezone/Makefile @@ -23,7 +23,7 @@ subdir := timezone include ../Makeconfig others := zdump zic -tests := test-tz tst-timezone tst-tzset tst-bz28707 +tests := test-tz tst-timezone tst-tzset tst-bz28707 tst-bz29951 generated-dirs += testdata @@ -86,11 +86,13 @@ $(objpfx)tst-timezone.out: $(addprefix $(testdata)/, \ Europe/London) $(objpfx)tst-tzset.out: $(addprefix $(testdata)/XT, 1 2 3 4) $(objpfx)tst-bz28707.out: $(testdata)/XT5 +$(objpfx)tst-bz29951.out: $(testdata)/XT6 test-tz-ENV = TZDIR=$(testdata) tst-timezone-ENV = TZDIR=$(testdata) tst-tzset-ENV = TZDIR=$(testdata) tst-bz28707-ENV = TZDIR=$(testdata) +tst-bz29951-ENV = TZDIR=$(testdata) # Note this must come second in the deps list for $(built-program-cmd) to work. zic-deps = $(objpfx)zic $(leapseconds) yearistype diff --git a/timezone/testdata/XT6 b/timezone/testdata/XT6 new file mode 100644 index 0000000000..07b393bb7d Binary files /dev/null and b/timezone/testdata/XT6 differ diff --git a/timezone/tst-bz29951.c b/timezone/tst-bz29951.c new file mode 100644 index 0000000000..abd334683b --- /dev/null +++ b/timezone/tst-bz29951.c @@ -0,0 +1,68 @@ +/* Check that daylight is set if the last DST transition did not change offset. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include + +/* Set the specified time zone with error checking. */ +static void +set_timezone (const char *name) +{ + TEST_VERIFY (setenv ("TZ", name, 1) == 0); + errno = 0; + tzset (); + TEST_COMPARE (errno, 0); +} + +static int +do_test (void) +{ + /* Test zone based on tz-2022g version of Africa/Tripoli. The last + DST transition coincided with a change in the standard time + offset, effectively making it a no-op. + + Africa/Tripoli Thu Oct 24 23:59:59 2013 UT + = Fri Oct 25 01:59:59 2013 CEST isdst=1 gmtoff=7200 + Africa/Tripoli Fri Oct 25 00:00:00 2013 UT + = Fri Oct 25 02:00:00 2013 EET isdst=0 gmtoff=7200 + */ + set_timezone ("XT6"); + TEST_VERIFY (daylight != 0); + TEST_COMPARE (timezone, -7200); + + /* Check that localtime re-initializes the two variables. */ + daylight = timezone = 17; + time_t t = 844034401; + struct tm *tm = localtime (&t); + TEST_VERIFY (daylight != 0); + TEST_COMPARE (timezone, -7200); + TEST_COMPARE (tm->tm_year, 96); + TEST_COMPARE (tm->tm_mon, 8); + TEST_COMPARE (tm->tm_mday, 29); + TEST_COMPARE (tm->tm_hour, 23); + TEST_COMPARE (tm->tm_min, 0); + TEST_COMPARE (tm->tm_sec, 1); + TEST_COMPARE (tm->tm_gmtoff, 3600); + TEST_COMPARE (tm->tm_isdst, 0); + + return 0; +} + +#include