-diff -Nur aMule-2.2.5-orig/configure.in aMule-2.2.5/configure.in
---- aMule-2.2.5-orig/configure.in 2009-05-16 09:38:01.000000000 +0200
-+++ aMule-2.2.5/configure.in 2009-09-18 20:01:47.000000000 +0200
-@@ -538,7 +538,7 @@
- AS_IF([test -n "$with_libupnp_prefix"], [libupnp_place=" (in $with_libupnp_prefix)"])
- AS_IF([test x${ENABLE_UPNP} = xyes], [dnl
- echo " libupnp ${LIBUPNP_VERSION:-Not detected}${libupnp_place:-}"
--])dnl
-+])
- if test x${WEB:-no} != xno; then
- AS_IF([test $regex_found = no],
- [regex_found="Not detected"],
-diff -Nur aMule-2.2.5-orig/m4/libupnp.m4 aMule-2.2.5/m4/libupnp.m4
---- aMule-2.2.5-orig/m4/libupnp.m4 2009-03-28 20:29:59.000000000 +0100
-+++ aMule-2.2.5/m4/libupnp.m4 2009-09-18 20:01:01.000000000 +0200
-@@ -76,7 +76,7 @@
- ], [dnl
- result=no
- resultstr=" (pkg-config not found)"
-- ])dnl
-+ ])
- AC_MSG_RESULT([$result$resultstr])
- libupnp_error="libupnp >= MIN_LIBUPNP_VERSION not found$resultstr"
- ], [dnl
+diff -Nur aMule-2.3.1-orig/m4/libpng.m4 aMule-2.3.1/m4/libpng.m4
+--- aMule-2.3.1-orig/m4/libpng.m4 2011-10-08 21:05:07.000000000 +0200
++++ aMule-2.3.1/m4/libpng.m4 2012-02-05 14:08:00.000000000 +0100
+@@ -95,9 +95,9 @@
+ SAVED_LDFLAGS=$LDFLAGS
+ SAVED_LIBS=$LIBS
+
+- CFLAGS+=" $LIBPNG_CFLAGS"
+- LDFLAGS+=" $LIBPNG_LDFLAGS"
+- LIBS+=" $LIBPNG_LIBS"
++ CFLAGS="$CFLAGS $LIBPNG_CFLAGS"
++ LDFLAGS="$LDFLAGS $LIBPNG_LDFLAGS"
++ LIBS="$LIBS $LIBPNG_LIBS"
+
+ AC_LINK_IFELSE([
+ AC_LANG_PROGRAM([[