Re: png Error while linking gui

[Riccardo Mottola]

Hi Fred,

Fred Kiefer wrote:
> PNG 1.2 is the most widespread around. I will check what version my
> > NetBSD box has, which has also the oldest version of cairo we support,
> > so it would mace sense to about sync them.
> >
> > http://refspecs.linuxfoundation.org/LSB_3.1.1/LSB-Desktop-generic/LSB-Desktop-generic/libpng12-ddefs.html 
> >
> >
> >
> > describes png_sizeof() as a macro
> >
> > For now, during code-freeze, something like this should suffice:
> >
> >
> > Index: Source/NSBitmapImageRep+PNG.m
> > ===================================================================
> > --- Source/NSBitmapImageRep+PNG.m       (revision 36173)
> > +++ Source/NSBitmapImageRep+PNG.m       (working copy)
> > @@ -48,6 +48,10 @@
> >
> >   #endif /* HAVE_LIBPNG */
> >
> > +#if !defined png_sizeof
> > +#define png_sizeof(x) sizeof(x)
> > +#endif
> > +
> >   /* we import all the standard headers to allow compilation without 
> > PNG */
> >   #import <Foundation/NSData.h>
> >   #import <Foundation/NSDictionary.h>
>
> In you changelog entry you stated that your change would work for 
> libpng 1.6, but as far as I can see that function is gone for that 
> release. Did you mean 1.5 instead?
>
> I reverted you change and replace it with something that should work 
> with libpng 1.6 as well. I think that the call to png_info_init_3() 
> was never needed, but left it in to not break older libraries.
I am working on 1.6... and the patch does indeed that: since 1.2 at 
least png_sizeof() was defined to sizeof() exactly as in my small patch. 
In 1.6 they removed this, thus my patch checked for the symbol and 
declared it back, it has always been a commodity macro anyway. It is 
just a stop-gap solution, but it worked and compiled for me. i thought 
tis was the minimum impact.
Why do you think it did not work?

Riccardo