New file. Used by strftime.m4.

diff --git a/m4/tzset.m4 b/m4/tzset.m4
new file mode 100644 (file)
index 0000000..dbe38c9
--- /dev/null
+++ b/m4/tzset.m4
@@ -0,0 +1,58 @@
+#serial 1
+# See if we have a working tzset function.
+# If so, arrange to compile the wrapper function.
+# For at least Solaris 2.5.1 and 2.6, this is necessary
+# because tzset can clobber the contents of the buffer
+# used by localtime.
+
+# Written by Paul Eggert and Jim Meyering.
+
+AC_DEFUN([gl_FUNC_TZSET],
+[
+  AC_REQUIRE([AC_HEADER_TIME])
+  AC_CACHE_CHECK([whether tzset works],
+                 gl_cv_func_tzset_vs_localtime,
+  [
+  AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
+#endif
+#include <stdlib.h>
+
+int
+main ()
+{
+  time_t t1 = 853958121;
+  struct tm *p, s;
+  putenv ("TZ=GMT0");
+  p = localtime (&t1);
+  s = *p;
+  putenv ("TZ=EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00");
+  tzset ();
+  exit (p->tm_year != s.tm_year
+        || p->tm_mon != s.tm_mon
+        || p->tm_mday != s.tm_mday
+        || p->tm_hour != s.tm_hour
+        || p->tm_min != s.tm_min
+        || p->tm_sec != s.tm_sec);
+}
+  ]])],
+       [gl_cv_func_tzset_vs_localtime=yes],
+       [gl_cv_func_tzset_vs_localtime=no],
+       [gl_cv_func_tzset_vs_localtime=no])])
+
+  AC_DEFINE(HAVE_RUN_TZSET_TEST, 1,
+    [Define to 1 if you have run the test for working tzset.])
+  if test $gl_cv_func_tzset_vs_localtime = yes; then
+    AC_LIBOBJ(tzset)
+    AC_DEFINE(tzset, rpl_tzset,
+      [Define to rpl_tzset if the wrapper function should be used.])
+  fi
+])