diff --git a/ChangeLog b/ChangeLog
index 573a35e5db..1469fbe724 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Fri Oct  4 14:23:08 2002  WATANABE Hirofumi  <eban@ruby-lang.org>
+
+	* configure.in (RUBY_PROG_GNU_LD): check whether the linker is GNU ld.
+
+	* ext/extmk.rb.in (create_makefile): add -Wl,-no-undefined to $DLDFLAGS
+	  on Linux if GNU ld is used and --enable-shared is specified.
+
+	* configure.in (RUBY_MINGW32): backport from 1.7.
+
 Thu Oct  3 20:09:52 2002  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
 
 	* ext/tcltklib/tcltklib.c (invoke_queue_handler): make singleton
diff --git a/configure.in b/configure.in
index aa1124eb2a..0efeb9a896 100644
--- a/configure.in
+++ b/configure.in
@@ -6,6 +6,46 @@ dnl workaround for autoconf 2.53
 m4_pattern_allow([^[L]IBOBJS$])
 '
 
+AC_DEFUN(RUBY_MINGW32,
+[case "$host_os" in
+cygwin*)
+AC_CACHE_CHECK(for mingw32 environment, rb_cv_mingw32,
+[AC_TRY_CPP([
+#ifndef __MINGW32__
+# error
+#endif
+], rb_cv_mingw32=yes,rb_cv_mingw32=no)
+rm -f conftest*])
+test "$rb_cv_mingw32" = yes && target_os="mingw32"
+  ;;
+esac])
+
+AC_DEFUN(RUBY_CPPOUTFILE,
+[AC_CACHE_CHECK(whether ${CPP} accepts -o, rb_cv_cppoutfile,
+[cppflags=$CPPFLAGS
+CPPFLAGS='-o conftest.i'
+AC_TRY_CPP([], rb_cv_cppoutfile=yes, rb_cv_cppoutfile=no)
+if test "$rb_cv_cppoutfile" = yes; then
+  CPPOUTFILE=$CPPFLAGS
+else
+  CPPOUTFILE='> conftest.i'
+fi
+CPPFLAGS=$cppflags
+AC_SUBST(CPPOUTFILE)
+rm -f conftest*])
+])
+
+AC_DEFUN(RUBY_PROG_GNU_LD,
+[AC_CACHE_CHECK(whether the linker is GNU ld, rb_cv_prog_gnu_ld,
+[if `$CC --print-prog-name=ld` -v 2>&1 | grep "GNU ld" > /dev/null; then
+  rb_cv_prog_gnu_ld=yes
+else
+  rb_cv_prog_gnu_ld=no
+fi
+])
+GNU_LD=$rb_cv_prog_gnu_ld
+AC_SUBST(GNU_LD)])
+
 rb_version=`grep RUBY_VERSION $srcdir/version.h`
 MAJOR=`expr "$rb_version" : '#define RUBY_VERSION "\([0-9][0-9]*\)\.[0-9][0-9]*\.[0-9][0-9]*"'`
 MINOR=`expr "$rb_version" : '#define RUBY_VERSION "[0-9][0-9]*\.\([0-9][0-9]*\)\.[0-9][0-9]*"'`
@@ -91,6 +131,14 @@ fi
 AC_PROG_CC
 AC_PROG_GCC_TRADITIONAL
 
+RUBY_PROG_GNU_LD
+RUBY_CPPOUTFILE
+
+OUTFLAG='-o '
+AC_SUBST(OUTFLAG)
+
+RUBY_MINGW32
+
 AC_PROG_YACC
 AC_CHECK_TOOL(RANLIB, ranlib, :)
 AC_CHECK_TOOL(AR, ar)
@@ -550,7 +598,7 @@ if test "$with_dln_a_out" != yes; then
 			rb_cv_dlopen=yes;;
 	solaris*) 	if test "$GCC" = yes; then
 			   LDSHARED='$(CC) -Wl,-G'
-			   if `$CC --print-prog-name=ld` -v 2>&1 | grep "GNU ld" > /dev/null; then
+			   if test "$rb_cv_prog_gnu_ld" = yes; then
 	 		       LDFLAGS="-Wl,-E"
 			       LDSHARED="$LDSHARED -shared"
 			   fi
@@ -577,7 +625,7 @@ if test "$with_dln_a_out" != yes; then
 			    LDFLAGS="-rdynamic"
 			    DLDFLAGS='-Wl,-soname,$(.TARGET)'
 			else
-			  test "$GCC" = yes && `$CC --print-prog-name=ld` -v 2>&1 | grep "GNU ld" > /dev/null || LDSHARED="ld -Bshareable"
+			  test "$GCC" = yes && test "$rb_cv_prog_gnu_ld" = yes || LDSHARED="ld -Bshareable"
 			fi
 			rb_cv_dlopen=yes ;;
 	netbsd*)	LDSHARED='${CC} -shared'
diff --git a/ext/extmk.rb.in b/ext/extmk.rb.in
index e82e6abb27..dceed036ab 100644
--- a/ext/extmk.rb.in
+++ b/ext/extmk.rb.in
@@ -377,6 +377,9 @@ def create_makefile(target)
   end
 
   $DLDFLAGS = '@DLDFLAGS@'
+  if /linux/ =~ RUBY_PLATFORM and $configure_args['--enable-shared'] and "@GNU_LD@" == "yes"
+    $DLDFLAGS << " -Wl,-no-undefined"
+  end
 
   if $configure_args['--enable-shared'] or "@LIBRUBY@" != "@LIBRUBY_A@"
     $libs = "@LIBRUBYARG@ " + $libs
diff --git a/version.h b/version.h
index 2d825c9d26..94e22fe019 100644
--- a/version.h
+++ b/version.h
@@ -1,4 +1,4 @@
 #define RUBY_VERSION "1.6.8"
-#define RUBY_RELEASE_DATE "2002-10-03"
+#define RUBY_RELEASE_DATE "2002-10-04"
 #define RUBY_VERSION_CODE 168
-#define RUBY_RELEASE_CODE 20021003
+#define RUBY_RELEASE_CODE 20021004