Bug#523280: localtime doesn't count leap seconds near 2038
On Thu, Apr 09, 2009 at 02:55:48PM +0900, Tanaka Akira wrote:
> Package: libc6
> Version: 2.7-18
>
> I found that date command doesn't work well with leap
> seconds after 2037-11-01 with right/EST5EDT timezone.
>
> % TZ=right/EST5EDT date -d @2140668023
> Sun Nov 1 01:59:59 EDT 2037
> % TZ=right/EST5EDT date -d @2140668024
> Sun Nov 1 01:00:24 EST 2037
>
> The second after 01:59:59 EDT should be 01:00:00 EST, not
> 01:00:24 EST.
This is a problem on 32-bit machines only, because it is very close to
2^31 - 1.
> It seems a problem of localtime().
>
> % cat localtime.c
> #include <stdlib.h>
> #include <stdio.h>
> #include <time.h>
>
> int main(int argc, char *argv[])
> {
> time_t t;
> struct tm *tmp;
>
> t = atol(argv[1]);
>
> tmp = localtime(&t);
> if (tmp == NULL) { fprintf(stderr, "localtime error\n"); exit(1); }
>
> printf("%d-%02d-%02d %02d:%02d:%02d %s %s (%ld) %ld\n",
> tmp->tm_year + 1900, tmp->tm_mon + 1, tmp->tm_mday,
> tmp->tm_hour, tmp->tm_min, tmp->tm_sec,
> tmp->tm_isdst > 0 ? "dst" : tmp->tm_isdst == 0 ? "std" : "unknown",
> tmp->tm_zone, tmp->tm_gmtoff,
> t);
>
> return 0;
> }
> % gcc -Wall localtime.c
> % TZ=right/EST5EDT ./a.out 2140668023
> 2037-11-01 01:59:59 dst EDT (-14400) 2140668023
> % TZ=right/EST5EDT ./a.out 2140668024
> 2037-11-01 01:00:24 std EST (-18000) 2140668024
>
> % dpkg -l|grep libc6
> ii libc6 2.7-18 GNU C Library: Shared libraries
> ii libc6-dbg 2.7-18 GNU C Library: Libraries with debugging symbols
> ii libc6-dev 2.7-18 GNU C Library: Development Libraries and Header Files
> ii libc6-i686 2.7-18 GNU C Library: Shared libraries [i686 optimized]
> % dpkg -l|grep tz
> ii tzdata 2008h-2 time zone and daylight-saving time data
> % uname -a
> Linux nute 2.6.26-1-486 #1 Fri Mar 13 17:25:45 UTC 2009 i686 GNU/Linux
>
> This problem may be related to #522949.
> "TZ=Egypt date -d 'Dec 1 00:00:00 2037' prints UTC date."
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=522949
Same here, this bug is only reproducible on 32-bit machines.
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurelien@aurel32.net http://www.aurel32.net
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