From 983ae185695f357f187a82a45fd5d8db920ab978 Mon Sep 17 00:00:00 2001
From: Ken Brown <kbrown@cornell.edu>
Date: Sun, 31 Oct 2010 19:21:53 -0400
Subject: [PATCH] * configure.in (checking whether localtime caches TZ): Use
 unsetenv instead of modifying environment directly.

---
 ChangeLog    |  5 +++++
 configure    | 12 ++----------
 configure.in | 12 ++----------
 3 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 4e6cd3d3deb..33a7cf784ab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-10-31  Ken Brown  <kbrown@cornell.edu>
+
+	* configure.in (checking whether localtime caches TZ): Use
+	unsetenv instead of modifying environment directly.
+
 2010-10-25  Andreas Schwab  <schwab@linux-m68k.org>
 
 	* configure.in (checking for -znocombreloc): Use AC_LANG_PROGRAM
diff --git a/configure b/configure
index c12401e2d16..3e3f91d4537 100755
--- a/configure
+++ b/configure
@@ -13982,14 +13982,6 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <time.h>
-extern char **environ;
-unset_TZ ()
-{
-  char **from, **to;
-  for (to = from = environ; (*to = *from); from++)
-    if (! (to[0][0] == 'T' && to[0][1] == 'Z' && to[0][2] == '='))
-      to++;
-}
 char TZ_GMT0[] = "TZ=GMT0";
 char TZ_PST8[] = "TZ=PST8";
 main()
@@ -13999,13 +13991,13 @@ main()
   if (putenv (TZ_GMT0) != 0)
     exit (1);
   hour_GMT0 = localtime (&now)->tm_hour;
-  unset_TZ ();
+  unsetenv("TZ");
   hour_unset = localtime (&now)->tm_hour;
   if (putenv (TZ_PST8) != 0)
     exit (1);
   if (localtime (&now)->tm_hour == hour_GMT0)
     exit (1);
-  unset_TZ ();
+  unsetenv("TZ");
   if (localtime (&now)->tm_hour != hour_unset)
     exit (1);
   exit (0);
diff --git a/configure.in b/configure.in
index fb64f0b346a..d53830b5ba2 100644
--- a/configure.in
+++ b/configure.in
@@ -2952,14 +2952,6 @@ AC_MSG_CHECKING(whether localtime caches TZ)
 AC_CACHE_VAL(emacs_cv_localtime_cache,
 [if test x$ac_cv_func_tzset = xyes; then
 AC_TRY_RUN([#include <time.h>
-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++;
-}
 char TZ_GMT0[] = "TZ=GMT0";
 char TZ_PST8[] = "TZ=PST8";
 main()
@@ -2969,13 +2961,13 @@ main()
   if (putenv (TZ_GMT0) != 0)
     exit (1);
   hour_GMT0 = localtime (&now)->tm_hour;
-  unset_TZ ();
+  unsetenv("TZ");
   hour_unset = localtime (&now)->tm_hour;
   if (putenv (TZ_PST8) != 0)
     exit (1);
   if (localtime (&now)->tm_hour == hour_GMT0)
     exit (1);
-  unset_TZ ();
+  unsetenv("TZ");
   if (localtime (&now)->tm_hour != hour_unset)
     exit (1);
   exit (0);
-- 
2.39.5