--- espgs/src/configure.ac.orig	2005-05-11 00:53:11.000000000 +0900
+++ espgs/src/configure.ac	2005-05-11 14:35:33.000000000 +0900
@@ -179,7 +179,48 @@ dnl ------------------------------------
 
 AC_CHECK_LIB(m, cos)
 dnl AC_CHECK_LIB(pthread, pthread_create)
-AC_CHECK_FUNC(iconv_open)
+dnl *** Tests for iconv ***
+AC_ARG_WITH(libiconv,
+            [AC_HELP_STRING([--with-libiconv=@<:@no/gnu/native@:>@],
+                            [use the libiconv library])],,
+	    [with_libiconv=maybe])
+found_iconv=no
+case $with_libiconv in
+  maybe)
+    # Check in the C library first
+    AC_CHECK_FUNC(iconv_open, [with_libiconv=no; found_iconv=yes])
+    # Check if we have GNU libiconv
+    if test $found_iconv = "no"; then
+      AC_CHECK_LIB(iconv, libiconv_open, [with_libiconv=gnu; found_iconv=yes])
+    fi
+    # Check if we have a iconv in -liconv, possibly from vendor
+    if test $found_iconv = "no"; then
+      AC_CHECK_LIB(iconv, iconv_open, [with_libiconv=native; found_iconv=yes])
+    fi
+    ;;
+  no)
+    AC_CHECK_FUNC(iconv_open, [with_libiconv=no; found_iconv=yes])
+    ;;
+  gnu|yes)
+    AC_CHECK_LIB(iconv, libiconv_open, [with_libiconv=gnu; found_iconv=yes])
+    ;;
+  native)
+    AC_CHECK_LIB(iconv, iconv_open, [with_libiconv=native; found_iconv=yes])
+    ;;
+esac
+if test x$with_libiconv != xno ; then
+  LIBS="$LIBS -liconv"
+fi
+
+case $with_libiconv in
+  gnu)
+    AC_DEFINE(USE_LIBICONV_GNU, 1, [Using GNU libiconv])
+    ;;
+  native)
+    AC_DEFINE(USE_LIBICONV_NATIVE, 1, [Using a native implementation of iconv in a separate library])
+    ;;
+esac
+
 AC_CHECK_LIB(dl, dlopen)
 
 AC_MSG_CHECKING([for local jpeg library source])
@@ -656,7 +697,7 @@ while test -n "$drivers"; do
 		;;
         opvp)
 		# Open Vector Printing driver...
-		if test x$ac_cv_lib_dl_dlopen != xno -a x$ac_cv_func_iconv_open != xno; then
+		if test x$ac_cv_lib_dl_dlopen != xno -a x$found_iconv != xno; then
 			P_DEVS="$P_DEVS opvp"
 		else
 			AC_MSG_WARN(Unable to include opvp driver due to missing prerequisites...)