--- configure.ac.orig	2003-02-08 23:53:42.000000000 -0500
+++ configure.ac	2003-08-07 21:10:37.000000000 -0400
@@ -13,11 +13,17 @@
 AH_TEMPLATE(BACKCHANNEL, [Enable BackChannel communication])
 AC_ARG_WITH(backchannel,
 	[  --without-backchannel		disable backchannel method],
-	,AC_DEFINE(BACKCHANNEL))
+	, [ with_backchannel=yes ])
+if test "x$with_backchannel" = "xyes"; then
+	AC_DEFINE(BACKCHANNEL)
+fi
 AH_TEMPLATE(ALLOW24BPP, [Enable 24 bit per pixel in native framebuffer])
 AC_ARG_WITH(24bpp,
 	[ --without-24bpp			disable 24 bpp framebuffers],
-	,AC_DEFINE(ALLOW24BPP))
+	, [ with_24bpp=yes ])
+if test "x$with_24bpp" = "xyes"; then
+	AC_DEFINE(ALLOW24BPP)
+fi
 
 # Checks for X libraries
 HAVE_X="false"
@@ -35,28 +41,36 @@
 AM_CONDITIONAL(HAVE_X, test $HAVE_X != "false")
 
 # Checks for libraries.
-AC_CHECK_HEADERS(jpeglib.h pthread.h zlib.h)
-if test ! -z "$HAVE_JPEGLIB.H"; then
-	AC_CHECK_LIB(jpeg, jpeg_CreateCompress)
+AC_ARG_WITH(jpeg,
+	[ --without-jpeg			disable support for jpeg],
+	, [ with_jpeg=yes ])
+if test "x$with_jpeg" = "xyes"; then
+	AC_CHECK_HEADER(jpeglib.h,
+		[ AC_CHECK_LIB(jpeg, jpeg_CreateCompress) ])
 fi
+AC_CHECK_HEADERS(pthread.h)
 if test ! -z "$HAVE_PTHREAD.H"; then
 	AC_CHECK_LIB(pthread, pthread_mutex_lock)
 	AC_CHECK_LIB(pthread, pthread_mutex_lock, HAVE_LIBPTHREAD="true")
 fi
 #AM_CONDITIONAL(HAVE_LIBPTHREAD, test ! -z "$HAVE_PTHREAD.H")
 AM_CONDITIONAL(HAVE_LIBPTHREAD, test ! -z "$HAVE_LIBPTHREAD")
-if test ! -z "$HAVE_ZLIB.H"; then
-	AC_CHECK_LIB(z, deflate)
-	# check for c++, but don't fail if not found
-	AC_CHECK_PROGS(CXX,[g++ c++ gpp aCC CC cxx cc++ cl FCC KCC RCC xlC_r xlC],none)
-	AH_TEMPLATE(HAVE_ZRLE, [Use zrle compression; needs a c++ compiler])
-	if test x$CXX != xnone; then
-		AC_DEFINE(HAVE_ZRLE)
-		AC_PROG_CXX
-		CCLD="\$(CXX)"
-	fi
-else
-	CXX=none
+AC_ARG_WITH(zlib,
+	[ --without-zlib			disable support for deflate],
+	, [ with_zlib=yes ])
+if test "x$with_zlib" = "xyes"; then
+	AC_CHECK_HEADER(zlib.h,
+		[
+		AC_CHECK_LIB(z, deflate)
+		# check for c++, but don't fail if not found
+		AC_CHECK_PROGS(CXX,[g++ c++ gpp aCC CC cxx cc++ cl FCC KCC RCC xlC_r xlC],none)
+		AH_TEMPLATE(HAVE_ZRLE, [Use zrle compression; needs a c++ compiler])
+		if test x$CXX != xnone; then
+			AC_DEFINE(HAVE_ZRLE)
+			AC_PROG_CXX
+			CCLD="\$(CXX)"
+		fi
+		], [ CXX=none ])
 fi
 AM_CONDITIONAL(HAVE_CXX, test x$CXX != xnone)
 AC_SUBST(CCLD)