When converting number of days since epoch (32-bits) to seconds,
calculations using 32-bit `long` overflow for years above 2038. Solve
this by casting number of days to `time_t` just before final
multiplication.
Signed-off-by: Freddie Chopin <freddie.chopin@gmail.com>
* libc/include/time.h (__tzrule_struct): Make offset long, since
a 16-bit int overflows on a 12-hour offset.
* libc/sys/linux/include/time.h: Ditto.
* libc/time/mktime.c (mktime): Use new type of __tzrule.offset.
* libc/time/mktm_r.c: Ditto.
* libc/time/gettzinfo.c: Ditto.
* libc/time/strftime.c (strftime): Fix '%x' to deal with negative
years. Fix '%z' to use long, not int.
* libc/include/time.h [!CYGWIN](_timezone): Change to long.
(__tzrule_type, __tzinfo_type): New types.
(__gettzinfo): New function.
* libc/sys/linux/include/time.h: Ditto.
* libc/time/Makefile.am: Add gettzinfo.c.
* libc/time/Makefile.in: Regenerated.
* libc/time/local.h: Moved __tzrule_type to time.h.
* libc/time/mktime.c: Call __gettzinfo to reference
__tznorth, __tzyear, and __tzrule array.
* libc/time/mktm_r.c: Ditto.
* libc/time/strftime.c: Ditto.
* libc/time/tzset_r.c: Ditto. Also remove definition
of __tzrule which is now in gettzinfo.c. Change _timezone
references to not cast to time_t.
* libc/time/gettzinfo.c: New file.
* libc/include/time.h (tzset, _tzset_r): Added prototypes.
(strptime): Moved prototype to be within !__STRICT_ANSI__.
(_tzname, _daylight, _timezone): No long __CYGWIN__ only.
(tzname): Defined for all platforms.
(daylight, timezone): Defined only for CYGWIN.
* libc/sys/linux/machine/i386/crt0.c: Add call to tzset() after
environment set up.
* libc/stdlib/setenv_r.c (_setenv_r): Call tzset() if the TZ
environment variable is set.
* libc/time/Makefile.am: Add support for tzset.c, tzlock.c, and
tzset_r.c.
* libc/time/Makefile.in: Regenerated.
* libc/time/gmtime.c (gmtime): Changed to call gmtime_r.
* libc/time/gmtime_r.c (gmtime_r): Changed to call _mktm_r.
* libc/time/lcltime_r.c (lcltime_r): Ditto.
* libc/time/local.h: New local header file.
* libc/time/mktime.c (mktime): Add timezone support.
* libc/time/mktm_r.c: New file which is the common engine
for gmtime_r and lcltime_r. This code has timezone support.
* libc/time/strftime.c (strftime): Add %Z timezone support.
* libc/time/tzlock.c: New file containing timezone lock stubs.
* libc/time/tzset.c: New file containing tzset() routine.
* libc/time/tzset_r.c: New file containing _tzset_r and
internal routine for calculating timezone changes for specified year.
Freddie Chopin