- In the previous build no symbols were exported in the resulting DLL

making this package unusable. This should be fixed for now (but may
    need more research)

mingw32-libpng-fix-invalid-exports.patch

@@ -0,0 +1,14 @@
+--- configure.orig	2009-11-20 01:18:09.926590381 +0100
++++ configure	2009-11-20 01:18:37.352678377 +0100
+@@ -11447,10 +11447,7 @@
+ if test "$have_ld_version_script" = "yes"; then
+     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for symbol prefix" >&5
+ $as_echo_n "checking for symbol prefix... " >&6; }
+-    SYMBOL_PREFIX=`echo "PREFIX=__USER_LABEL_PREFIX__" \
+-                   | ${CPP-${CC-gcc} -E} - 2>&1 \
+-                   | ${EGREP-grep} "^PREFIX=" \
+-                   | ${SED-sed} "s:^PREFIX=::"`
++    SYMBOL_PREFIX=""
+ 
+     { $as_echo "$as_me:${as_lineno-$LINENO}: result: $SYMBOL_PREFIX" >&5
+ $as_echo "$SYMBOL_PREFIX" >&6; }

mingw32-libpng.spec

@@ -6,7 +6,7 @@
 
 Name:           mingw32-libpng
 Version:        1.2.40
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        MinGW Windows Libpng library
 
 License:        zlib
@@ -14,6 +14,7 @@ URL:            http://www.libpng.org/pub/png/
 Source0:        ftp://ftp.simplesystems.org/pub/png/src/libpng-%{version}.tar.bz2
 Patch0:         libpng-multilib.patch
 Patch1:         libpng-pngconf.patch
+Patch2:         mingw32-libpng-fix-invalid-exports.patch
 
 Group:          Development/Libraries
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -36,6 +37,14 @@ MinGW Windows Libpng library.
 %patch0 -p1
 %patch1 -p1
 
+# The configure script tries to generate a prefix which is used for
+# symbol declarations. However, when this prefix is prefix is used
+# the resulting DLL's don't have any exported symbols at all
+# When we drop this prefix we retain backwards compatibility with
+# older versions of mingw32-libpng. We might need to research this
+# issue more to find out the real cause, but this will do for now
+%patch2 -p0
+
 
 %build
 %{_mingw32_configure}
@@ -78,6 +87,10 @@ rm -rf $RPM_BUILD_ROOT
 
 
 %changelog
+* Fri Nov 20 2009 Erik van Pienbroek <epienbro@fedoraproject.org> - 1.2.40-2
+- In the previous build no symbols were exported in the resulting DLL making this
+  package unusable. This should be fixed for now (but may need more research)
+
 * Thu Nov  5 2009 Richard W.M. Jones <rjones@redhat.com> - 1.2.40-1
 - New upstream version 1.2.40.