Fix for libpng undefined symbol

[Hans de Goede]

Thomas Fitzsimmons wrote:
> Hi,
> 
> With the update to b18 the build was failing on my x86_64 machine with 
> an undefined symbol, png_mmx_support, in libpng.
> 
> The problem was exposed by the fix for:
> 
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6577886
> 
> specifically this line:
> 
> +LDFLAGS_DEFS_OPTION  = -z defs
> 
> which causes the linker to disallow undefined symbols.
> 
> The failure will happen on systems that support MMX:
> 
> $ echo | cpp -dM | grep __MMX__
> #define __MMX__ 1
> 
> That macro indirectly causes the default png_mmx_support definition to 
> be ifdef'd out.
> 
> For now I've applied this workaround:
> 
> --- openjdk.orig/j2se/make/sun/splashscreen/Makefile    2007-08-19 
> 15:04:21.000000000 -0400
> +++ openjdk/j2se/make/sun/splashscreen/Makefile 2007-08-19 
> 15:08:45.000000000 -0400
> @@ -59,7 +59,7 @@
>  # C Flags
>  #
> 
> -CFLAGS += -DSPLASHSCREEN
> +CFLAGS += -DSPLASHSCREEN -DPNG_NO_MMX_CODE
> 
>  ifneq ($(PLATFORM), windows)
>    CFLAGS += -DWITH_X11
> 
> to disable libpng's MMX-specific functions (optimized C implementations 
> are used instead).
> 
> A better solution would be to conditionally compile pnggccrd.c, which 
> defines png_mmx_support, when __MMX__ is defined.  pnggccrd.c would have 
> to be patched to fix png_squelch_warnings compile errors.
> 

Hmm,

This sounds awefully familiar to a bug in the system libpng, which I fixed 
quite some time ago. Is IcedTea using its own copy of libpng? IF so why?

Regards,

Hans