[PATCH] Allow usage of external zlib copy

[Phil Race]

Petteri Räty wrote:
> Phil Race kirjoitti:
>   
>> Complicating matters further there are some additonal changes not in the
>> 'openjdk' until we
>> sort out more legal issues. If we can't work those out these embedded
>> changes would mean
>> the commercial JDK would simply not be able to use  an external libjpeg.
>> and  there'd be
>> an  annoying difference betwen the two builds
>>
>>     
>
> But it's important to remember that if OpenJDK is going to be fully
> embraced by Linux distributions, normal users are not going to be using
> your builds at all and distributions will be using external libraries if
> at all possible.
>   

Right. Where possible. libjpeg  happens to be a special case.
We do use platform libs for the most part. 
Taking it to a silly extreme we obviously would not bundle a libX11.
Its gotta be there.

A big part of the reason things are bundled is when you *do* need them 
but have
no idea if they'll be there. If you are building on gentoo for gentoo 
you can control that better

But we also use libcups, libfontconfig., and  we test for them using 
dlopen so don't explictly link ..
if we can't find them we use other approaches.

At some point if we use these a whole lot more then dlsym gets tiresome 
and we'd
probably start depending on them at compile time. But our build 
platforms don't
necessarily have them.

Also for the font rasteriser we will defer to the platform installed 
version  : that will be
a straight compile time link.

So the big picture is to use the platform libs, and not duplicate.. 
there just happen to
be exceptions.

-phil.
> Regards,
> Petteri
> --
> Gentoo/Java project lead
>
>