Makefile.am              | 12 +++++++++---
 configure.ac             |  3 ++-
 pngconf.h                | 26 ++++++++++++++++++++++++--
 scripts/libpng-config.in | 10 +++++-----
 4 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 892521b..02fbc59 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -49,8 +49,8 @@ libpng_la_LDFLAGS = -rpath '$(libdir)' -no-undefined -export-dynamic \
 
 if HAVE_LD_VERSION_SCRIPT
   # Versioned symbols and restricted exports
-  libpng12_la_LDFLAGS += -Wl,--version-script=libpng.vers
-  libpng12_la_DEPENDENCIES = libpng.vers
+  libpng12_la_LDFLAGS += -Wl,--version-script=libpng.vers -Wl,libpng.lds
+  libpng12_la_DEPENDENCIES = libpng.vers libpng.lds
 else
   # Only restricted exports when possible
   libpng12_la_LDFLAGS += -export-symbols libpng.sym
@@ -114,9 +114,15 @@ libpng.sym: png.h pngconf.h
 
 libpng.vers: libpng.sym
 	rm -f $@ $@.new
-	echo PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0 '{global:' > $@.new
+	echo PNG_@PNGLIB_MAJOR@@PNGLIB_MINOR@ '{global:' > $@.new
 	$(SED) s/$$/\;/ libpng.sym >> $@.new
 	echo 'local: *; };' >> $@.new
+	echo 'PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0 {} PNG_@PNGLIB_MAJOR@@PNGLIB_MINOR@;' >> $@.new
+	mv $@.new $@
+
+libpng.lds: libpng.sym
+	rm -f $@ $@.new
+	$(SED) 's/^.*$$/"&@PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0" = &;/' libpng.sym >> $@.new
 	mv $@.new $@
 
 test: check
diff --git a/configure.ac b/configure.ac
index 8dc8e1f..de9cc8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -68,7 +68,8 @@ esac
 AC_MSG_CHECKING(
   [if assembler code in pnggccrd.c can be compiled without PNG_NO_MMX_CODE])
 AC_TRY_COMPILE(
-  [#include "$srcdir/pnggccrd.c"],
+  [#define PNG_CONFIGURE_LIBPNG
+   #include "$srcdir/pnggccrd.c"],
   [return 0;],
   AC_MSG_RESULT(yes)
   LIBPNG_NO_MMX="",
diff --git a/pngconf.h b/pngconf.h
index 3ae7a28..c65517d 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -38,6 +38,25 @@
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
+#else
+/* pngconf.h is part of the exported API. When a libpng-using application
+   includes us, PNG_CONFIGURE_LIBPNG is of course not defined as we do not have
+   libpng's config.h available in this case. This means that we do not have the
+   defines added to config.h and the commandline by libpng's ./configure .
+
+   For all defines from config.h not having them set is not a problem, however
+   ./configure also adds -DPNG_NO_ASSEMBLER_CODE to the CFLAGS when compiling
+   on a platform on which the MMX and SSE asm code in libpng is not supported.
+
+   We do need this define as this define is used to determine whether or not
+   to define PNG_ASSEMBLER_CODE_SUPPORTED and other assembler related defines
+   and prototypes. PNG_ASSEMBLER_CODE_SUPPORTED in turn is used by applications
+   (ImageMagick for example) to determine whether or not they can use the asm
+   functions. Thus we need to define PNG_NO_ASSEMBLER_CODE here on platforms
+   on which the MMX and SSE asm code in libpng is not supported: */
+#ifndef __i386__ /* change this if MMX/SSE become supported on x86_64! */
+#define PNG_NO_ASSEMBLER_CODE
+#endif
 #endif
 
 /*
@@ -377,8 +396,11 @@
 #        undef _BSD_SOURCE
 #      endif
 #      ifdef _SETJMP_H
-       /* If you encounter a compiler error here, see the explanation
-        * near the end of INSTALL.
+       /* If you encounter a compiler error here, this means you have
+        * compiled another module that includes setjmp.h, which is
+        * hazardous because the two modules might not include exactly
+        * the same setjmp.h.  Use the cexcept interface instead, as
+        * demonstrated in contrib/visupng of the libpng distribution.
         */
            __pngconf.h__ in libpng already includes setjmp.h;
            __dont__ include it again.;
diff --git a/scripts/libpng-config.in b/scripts/libpng-config.in
index 7ae7d50..1c7eda3 100755
--- a/scripts/libpng-config.in
+++ b/scripts/libpng-config.in
@@ -11,11 +11,11 @@
 
 # Modeled after libxml-config.
 
-version="@PNGLIB_VERSION@"
-prefix="@prefix@"
-exec_prefix="@exec_prefix@"
-libdir="@libdir@"
-includedir="@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+version=`pkg-config --modversion libpng`
+prefix=`pkg-config --variable prefix libpng`
+exec_prefix=`pkg-config --variable exec_prefix libpng`
+libdir=`pkg-config --variable libdir libpng`
+includedir=`pkg-config --variable includedir libpng`
 libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
 all_libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ @LIBS@"
 I_opts="-I${includedir}"