--- zlib-1.2.1/configure.multibuild	2003-11-17 04:50:39.000000000 +0100
+++ zlib-1.2.1/configure	2004-01-07 00:18:39.000000000 +0100
@@ -18,11 +18,12 @@
 # If you have problems, try without defining CC and CFLAGS before reporting
 # an error.
 
+top_srcdir=`dirname $0`
 LIBS=libz.a
 LDFLAGS="-L. ${LIBS}"
-VER=`sed -n -e '/VERSION "/s/.*"\(.*\)".*/\1/p' < zlib.h`
-VER2=`sed -n -e '/VERSION "/s/.*"\([0-9]*\\.[0-9]*\)\\..*/\1/p' < zlib.h`
-VER1=`sed -n -e '/VERSION "/s/.*"\([0-9]*\)\\..*/\1/p' < zlib.h`
+VER=`sed -n -e '/VERSION "/s/.*"\(.*\)".*/\1/p' < $top_srcdir/zlib.h`
+VER2=`sed -n -e '/VERSION "/s/.*"\([0-9]*\\.[0-9]*\)\\..*/\1/p' < $top_srcdir/zlib.h`
+VER1=`sed -n -e '/VERSION "/s/.*"\([0-9]*\)\\..*/\1/p' < $top_srcdir/zlib.h`
 AR=${AR-"ar rc"}
 RANLIB=${RANLIB-"ranlib"}
 prefix=${prefix-/usr/local}
@@ -182,10 +183,10 @@ cat > $test.c <<EOF
 int main() { return 0; }
 EOF
 if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
-  sed < zconf.in.h "/HAVE_UNISTD_H/s%0%1%" > zconf.h
+  sed < $top_srcdir/zconf.in.h "/HAVE_UNISTD_H/s%0%1%" > zconf.h
   echo "Checking for unistd.h... Yes."
 else
-  cp -p zconf.in.h zconf.h
+  cp -p $top_srcdir/zconf.in.h zconf.h
   echo "Checking for unistd.h... No."
 fi
 
@@ -424,7 +425,7 @@ esac
 rm -f $test.[co] $test $test$shared_ext
 
 # udpate Makefile
-sed < Makefile.in "
+sed < $top_srcdir/Makefile.in "
 /^CC *=/s#=.*#=$CC#
 /^CFLAGS *=/s#=.*#=$CFLAGS#
 /^CPP *=/s#=.*#=$CPP#
@@ -443,3 +444,10 @@ sed < Makefile.in "
 /^mandir *=/s#=.*#=$mandir#
 /^LDFLAGS *=/s#=.*#=$LDFLAGS#
 " > Makefile
+
+# symlink sources
+if test "$top_srcdir" != "."; then
+  for f in $top_srcdir/*.[ch]; do
+    ln -s $f `basename $f`
+  done
+fi