* m4/tzset.m4 (gl_FUNC_TZSET): Require AC_CANONICAL_HOST. On native
Windows, set REPLACE_TZSET to 1.
* lib/tzset.c (tzset): On native Windows, fix TZ if necessary, and
invoke '_tzset' instead of 'tzset'.
* doc/posix-functions/tzset.texi: Mention the native Windows workaround.
* modules/time_rz (Depends-on): Add tzset.
* lib/time_rz.c (tzset): Remove fallback definition.
* m4/time_rz.m4 (gl_TIME_RZ): Don't test for tzset.
Don't change tzname, as this makes MinGW dump core (Bug#21020).
Instead, store the tzname copy in the struct tm_zone object.
Problem reported by Eli Zaretskii in: http://bugs.gnu.org/21020#48
* lib/strftime.c [!_LIBC]:
* lib/time_rz.c: Include time-internal.h.
* lib/strftime.c (strftime_case_) [!HAVE_TM_ZONE]: Infer the zone
name from *TZ rather than from TZNAME, doable because *TZ now has
a tzname_copy member.
* lib/time-internal.h: New file, with contents taken from
lib/time_rz.c. It's separate because strftime.c now accesses
struct tm_zone members.
(struct tm_zone) [HAVE_TZNAME && !HAVE_TM_ZONE]:
New member tzname_copy.
* lib/time_rz.c (struct tm_zone): Move to time-internal.h.
(tzalloc) [HAVE_TZNAME && !HAVE_TM_ZONE]:
Initialize tzname_copy member.
(save_abbr) [HAVE_TZNAME && !HAVE_TM_ZONE]: Save abbreviation
in tzname_copy member.
(revert_tz) [HAVE_TZNAME]: Remove no-longer-needed tzname saving.
(restore_tzname): Remove; no longer needed. All calls removed.
* modules/time_rz (Files): Add lib/time-internal.h.
Bruno Haible