From 6e66311d0a5150e758ca5058abe1d0c748d9063f Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Tue, 7 Aug 2007 22:29:07 +0000
Subject: [PATCH] use unsetenv() instead of setenv(var, NULL) which is invalid

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@47942 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 configure             | 428 ++++++++++++++++++++++++++++++++----------
 configure.in          |   3 +
 setup.h.in            |   3 +
 setup.h_vms           |   1 +
 src/unix/utilsunx.cpp |  12 +-
 5 files changed, 344 insertions(+), 103 deletions(-)

diff --git a/configure b/configure
index 59794b8f92..a2af0fa0ab 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Id: configure.in 47558 2007-07-19 01:06:01Z VZ .
+# From configure.in Id: configure.in 47597 2007-07-20 18:27:35Z PC .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.59 for wxWidgets 2.8.4.
 #
@@ -16819,9 +16819,13 @@ done
 
 
 if test "$ac_cv_header_wchar_h" != "yes"; then
-    echo "$as_me:$LINENO: checking for wcstr.h" >&5
-echo $ECHO_N "checking for wcstr.h... $ECHO_C" >&6
-if test "${ac_cv_header_wcstr_h+set}" = set; then
+
+for ac_header in wcstr.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -16832,7 +16836,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 $ac_includes_default
 
-#include <wcstr.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -16855,18 +16859,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_wcstr_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_wcstr_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_wcstr_h" >&5
-echo "${ECHO_T}$ac_cv_header_wcstr_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
 fi
 
@@ -16882,9 +16893,13 @@ case "${host}" in
 esac
 
 if test "$USE_UNIX" = 1 ; then
-    echo "$as_me:$LINENO: checking for sys/select.h" >&5
-echo $ECHO_N "checking for sys/select.h... $ECHO_C" >&6
-if test "${ac_cv_header_sys_select_h+set}" = set; then
+
+for ac_header in sys/select.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -16895,7 +16910,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 $ac_includes_default
 
-#include <sys/select.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -16918,18 +16933,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_sys_select_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_sys_select_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_sys_select_h" >&5
-echo "${ECHO_T}$ac_cv_header_sys_select_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
 fi
 
@@ -22129,9 +22151,13 @@ ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ex
 ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 
 
-    echo "$as_me:$LINENO: checking for iostream" >&5
-echo $ECHO_N "checking for iostream... $ECHO_C" >&6
-if test "${ac_cv_header_iostream+set}" = set; then
+
+for ac_header in iostream
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -22142,7 +22168,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
 
-#include <iostream>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -22165,18 +22191,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_iostream=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_iostream=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_iostream" >&5
-echo "${ECHO_T}$ac_cv_header_iostream" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
 
     if test "$ac_cv_header_iostream" = "yes" ; then
@@ -26277,9 +26310,13 @@ TOOLKIT_INCLUDE=
 WIDGET_SET=
 
 if test "$USE_WIN32" = 1 ; then
-    echo "$as_me:$LINENO: checking for w32api.h" >&5
-echo $ECHO_N "checking for w32api.h... $ECHO_C" >&6
-if test "${ac_cv_header_w32api_h+set}" = set; then
+
+for ac_header in w32api.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -26290,7 +26327,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
 
-#include <w32api.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -26313,18 +26350,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_w32api_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_w32api_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_w32api_h" >&5
-echo "${ECHO_T}$ac_cv_header_w32api_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
     echo "$as_me:$LINENO: checking for windows.h" >&5
 echo $ECHO_N "checking for windows.h... $ECHO_C" >&6
@@ -31090,9 +31134,13 @@ fi
 
 if test "$wxUSE_GUI" = "yes"; then
     if test "$wxUSE_UNIX" = "yes" -a "$wxUSE_PM" != 1; then
-                echo "$as_me:$LINENO: checking for X11/Xlib.h" >&5
-echo $ECHO_N "checking for X11/Xlib.h... $ECHO_C" >&6
-if test "${ac_cv_header_X11_Xlib_h+set}" = set; then
+
+for ac_header in X11/Xlib.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -31103,7 +31151,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
 
-#include <X11/Xlib.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -31126,22 +31174,33 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_X11_Xlib_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_X11_Xlib_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_X11_Xlib_h" >&5
-echo "${ECHO_T}$ac_cv_header_X11_Xlib_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
 
 
-        echo "$as_me:$LINENO: checking for X11/XKBlib.h" >&5
-echo $ECHO_N "checking for X11/XKBlib.h... $ECHO_C" >&6
-if test "${ac_cv_header_X11_XKBlib_h+set}" = set; then
+for ac_header in X11/XKBlib.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -31156,7 +31215,7 @@ cat >>conftest.$ac_ext <<_ACEOF
                           #endif
 
 
-#include <X11/XKBlib.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -31179,18 +31238,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_X11_XKBlib_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_X11_XKBlib_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_X11_XKBlib_h" >&5
-echo "${ECHO_T}$ac_cv_header_X11_XKBlib_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
     fi
 fi
@@ -31553,9 +31619,13 @@ echo $ECHO_N "checking for Xxf86vm extension... $ECHO_C" >&6
             if test "$ac_find_libraries" != "" ; then
                 echo "$as_me:$LINENO: result: yes" >&5
 echo "${ECHO_T}yes" >&6
-                echo "$as_me:$LINENO: checking for X11/extensions/xf86vmode.h" >&5
-echo $ECHO_N "checking for X11/extensions/xf86vmode.h... $ECHO_C" >&6
-if test "${ac_cv_header_X11_extensions_xf86vmode_h+set}" = set; then
+
+for ac_header in X11/extensions/xf86vmode.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -31570,7 +31640,7 @@ cat >>conftest.$ac_ext <<_ACEOF
                                       #endif
 
 
-#include <X11/extensions/xf86vmode.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -31593,23 +31663,27 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_X11_extensions_xf86vmode_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_X11_extensions_xf86vmode_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_X11_extensions_xf86vmode_h" >&5
-echo "${ECHO_T}$ac_cv_header_X11_extensions_xf86vmode_h" >&6
-if test $ac_cv_header_X11_extensions_xf86vmode_h = yes; then
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
                                   GUI_TK_LIBRARY="$GUI_TK_LIBRARY -lXxf86vm"
 
 fi
 
+done
 
             else
                 echo "$as_me:$LINENO: result: no" >&5
@@ -34399,9 +34473,13 @@ _ACEOF
 #include <wchar.h>"
     case "${host}" in
         *-*-solaris2* )
-            echo "$as_me:$LINENO: checking for widec.h" >&5
-echo $ECHO_N "checking for widec.h... $ECHO_C" >&6
-if test "${ac_cv_header_widec_h+set}" = set; then
+
+for ac_header in widec.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -34412,7 +34490,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 $ac_includes_default
 
-#include <widec.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -34435,18 +34513,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_widec_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_widec_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_widec_h" >&5
-echo "${ECHO_T}$ac_cv_header_widec_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
             if test "$ac_cv_header_widec_h" = "yes"; then
                 wchar_headers="$wchar_headers
@@ -36232,6 +36317,109 @@ _ACEOF
 fi
 done
 
+if test "$ac_cv_func_setenv" = "yes"; then
+
+for ac_func in unsetenv
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $ac_func innocuous_$ac_func
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $ac_func
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char $ac_func ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+char (*f) () = $ac_func;
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+int
+main ()
+{
+return f != $ac_func;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  eval "$as_ac_var=yes"
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+eval "$as_ac_var=no"
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+fi
 
 HAVE_SOME_SLEEP_FUNC=0
 if test "$USE_BEOS" = 1; then
@@ -37434,9 +37622,13 @@ echo "$as_me:$LINENO: result: $ac_cv_lib_esd_esd_close" >&5
 echo "${ECHO_T}$ac_cv_lib_esd_esd_close" >&6
 if test $ac_cv_lib_esd_esd_close = yes; then
 
-    echo "$as_me:$LINENO: checking for esd.h" >&5
-echo $ECHO_N "checking for esd.h... $ECHO_C" >&6
-if test "${ac_cv_header_esd_h+set}" = set; then
+
+for ac_header in esd.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -37447,7 +37639,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
 
-#include <esd.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -37470,23 +37662,27 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_esd_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_esd_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_esd_h" >&5
-echo "${ECHO_T}$ac_cv_header_esd_h" >&6
-if test $ac_cv_header_esd_h = yes; then
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
     EXTRALIBS_ESD="-lesd"
 
 fi
 
+done
 
 
 fi
@@ -37966,9 +38162,13 @@ _ACEOF
 
       fi
 
-      echo "$as_me:$LINENO: checking for sched.h" >&5
-echo $ECHO_N "checking for sched.h... $ECHO_C" >&6
-if test "${ac_cv_header_sched_h+set}" = set; then
+
+for ac_header in sched.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -37979,7 +38179,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 $ac_includes_default
 
-#include <sched.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -38002,18 +38202,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_sched_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_sched_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_sched_h" >&5
-echo "${ECHO_T}$ac_cv_header_sched_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
       if test "$ac_cv_header_sched_h" = "yes"; then
           echo "$as_me:$LINENO: checking for sched_yield" >&5
@@ -43556,9 +43763,13 @@ echo "${ECHO_T}$wxUSE_JOYSTICK" >&6
 
         else
                 if test "$wxUSE_MGL" != "1"; then
-                                                                                    echo "$as_me:$LINENO: checking for linux/joystick.h" >&5
-echo $ECHO_N "checking for linux/joystick.h... $ECHO_C" >&6
-if test "${ac_cv_header_linux_joystick_h+set}" = set; then
+
+for ac_header in linux/joystick.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -43569,7 +43780,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 $ac_includes_default
 
-#include <linux/joystick.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -43592,21 +43803,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_linux_joystick_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_linux_joystick_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_linux_joystick_h" >&5
-echo "${ECHO_T}$ac_cv_header_linux_joystick_h" >&6
-if test $ac_cv_header_linux_joystick_h = yes; then
-  wxUSE_JOYSTICK=yes
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+ wxUSE_JOYSTICK=yes
 fi
 
+done
 
         fi
     fi
@@ -43843,9 +44058,13 @@ if test "$USE_WIN32" = 1 -a \( "$wxUSE_DATAOBJ"       = "yes" \
                           -o "$wxUSE_CLIPBOARD"     = "yes" \
                           -o "$wxUSE_OLE"     = "yes" \
                           -o "$wxUSE_DRAG_AND_DROP" = "yes" \) ; then
-    echo "$as_me:$LINENO: checking for ole2.h" >&5
-echo $ECHO_N "checking for ole2.h... $ECHO_C" >&6
-if test "${ac_cv_header_ole2_h+set}" = set; then
+
+for ac_header in ole2.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -43856,7 +44075,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
 
-#include <ole2.h>
+#include <$ac_header>
 _ACEOF
 rm -f conftest.$ac_objext
 if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
@@ -43879,18 +44098,25 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-  ac_cv_header_ole2_h=yes
+  eval "$as_ac_Header=yes"
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
-ac_cv_header_ole2_h=no
+eval "$as_ac_Header=no"
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
-echo "$as_me:$LINENO: result: $ac_cv_header_ole2_h" >&5
-echo "${ECHO_T}$ac_cv_header_ole2_h" >&6
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
 
+fi
+
+done
 
 
     if test "$ac_cv_header_ole2_h" = "yes" ; then
diff --git a/configure.in b/configure.in
index a1b5299b0d..bc1c9b4446 100644
--- a/configure.in
+++ b/configure.in
@@ -4954,6 +4954,9 @@ AC_CHECK_FUNCS(timegm)
 
 dnl look for a function to modify the environment
 AC_CHECK_FUNCS(setenv putenv, break)
+if test "$ac_cv_func_setenv" = "yes"; then
+    AC_CHECK_FUNCS(unsetenv)
+fi
 
 HAVE_SOME_SLEEP_FUNC=0
 if test "$USE_BEOS" = 1; then
diff --git a/setup.h.in b/setup.h.in
index 300ee5d7af..6deed3fd67 100644
--- a/setup.h.in
+++ b/setup.h.in
@@ -1025,6 +1025,9 @@
 /* Define if you have the uname function.  */
 #undef HAVE_UNAME
 
+/* Define if you have the unsetenv function.  */
+#undef HAVE_UNSETENV
+
 /* Define if you have the usleep function.  */
 #undef HAVE_USLEEP
 
diff --git a/setup.h_vms b/setup.h_vms
index 96a8354d17..408ceb4d28 100644
--- a/setup.h_vms
+++ b/setup.h_vms
@@ -897,6 +897,7 @@ typedef pid_t GPid;
 /* Define if you have the setenv function.  */
 #   if __CRTL_VER >= 70000000
 #define HAVE_SETENV 1
+#define HAVE_UNSETENV 1
 #else
 #undef HAVE_SETENV
 #endif
diff --git a/src/unix/utilsunx.cpp b/src/unix/utilsunx.cpp
index f5440a2f5a..fd523aef4c 100644
--- a/src/unix/utilsunx.cpp
+++ b/src/unix/utilsunx.cpp
@@ -1060,9 +1060,17 @@ bool wxGetEnv(const wxString& var, wxString *value)
 bool wxSetEnv(const wxString& variable, const wxChar *value)
 {
 #if defined(HAVE_SETENV)
+    if ( !value )
+    {
+#ifdef HAVE_UNSETENV
+        return unsetenv(variable.mb_str()) == 0;
+#else
+        value = _T(""); // we can't pass NULL to setenv()
+#endif
+    }
+
     return setenv(variable.mb_str(),
-                  value ? (const char *)wxString(value).mb_str()
-                        : NULL,
+                  wxString(value).mb_str(),
                   1 /* overwrite */) == 0;
 #elif defined(HAVE_PUTENV)
     wxString s = variable;