(LOCALTIME_CACHE): Also define if localtime mishandles unsetting TZ.

This works around a localtime bug in mips-dec-ultrix.

1 files changed, 19 insertions, 4 deletions

diff --git a/configure.in b/configure.in
index da8b2efc794..a977091e79f 100644
--- a/configure.in
+++ b/configure.in
@@ -3,7 +3,7 @@ dnl To rebuild the `configure' script from this, execute the command
 dnl     autoconf
 dnl in the directory containing this script.
 dnl
-dnl  Copyright (C) 1994, 1995 Free Software Foundation, Inc.
+dnl  Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc.
 dnl  
 dnl  This file is part of GNU Emacs.
 dnl  
@@ -1375,16 +1375,31 @@ AC_TRY_RUN([#include <time.h>
 #if STDC_HEADERS
 # include <stdlib.h>
 #endif
+extern char **environ;
+unset_TZ ()
+{
+  char **from, **to;
+  for (to = from = environ; (*to = *from); from++)
+    if (! (to[0][0] == 'T' && to[0][1] == 'Z' && to[0][2] == '='))
+      to++;
+}
 main()
 {
   time_t now = time ((time_t *) 0);
-  int hour;
+  int hour_GMT0, hour_unset;
   if (putenv ("TZ=GMT0") != 0)
     exit (1);
-  hour = localtime (&now)->tm_hour;
+  hour_GMT0 = localtime (&now)->tm_hour;
+  unset_TZ ();
+  hour_unset = localtime (&now)->tm_hour;
   if (putenv ("TZ=PST8") != 0)
     exit (1);
-  exit (localtime (&now)->tm_hour == hour);
+  if (localtime (&now)->tm_hour == hour_GMT0)
+    exit (1);
+  unset_TZ ();
+  if (localtime (&now)->tm_hour != hour_unset)
+    exit (1);
+  exit (0);
 }], emacs_cv_localtime_cache=no, emacs_cv_localtime_cache=yes,
 [# If we have tzset, assume the worst when cross-compiling.
 emacs_cv_localtime_cache=yes])