[tex-live] adding xetex code to TL tree

[Jonathan Kew]

TeX Live developers -

I'd like to propose that I create a branch (which is a cheap  
operation in Subversion) in the TL repository, and add the xetex  
source code there. (I haven't been around the TL world long enough to  
know what policies/practices are normal here, hence this message.)

By way of background: for the most part, the xetex code lives in its  
own subdirectory at source/texk/web2c/xetexdir. Adding this directory  
should have no adverse effect on the rest of the TL programs.  
Similarly for the xdvipdfmx driver, in source/texk/xdvipdfmx.

However, there are also some modifications to a few of the common  
files in source/texk/web2c: texmfmem.h, texmfmp.h, texmfmp-help.h,  
and lib/texmfmp.c. I believe all the xetex changes are contained  
within #ifdef XeTeX conditionals, so that they should not affect  
building anything else. So these changes should also be "safe",  
though they will be visible to the maintainers of the rest of the TeX  
family.

There will also be new libraries in /source/libs, and an update to  
the freetype2 sources already there. The latter might have an impact  
on building fpTeX on Windows, as this seems to depend on freetype2  
(it is not used in a normal Unix build, as far as I can tell).

Finally (and most far-reaching), there will need to be additions to  
the makefiles and configure scripts at various levels, to integrate  
xetex into the overall TL build process. In principle, this shouldn't  
break anything else; there will just be a few new options and  
targets. But of course if xetex itself fails to compile on certain  
systems (which I fully expect at this stage -- after all, TL gets  
built on platforms I've never even seen!) this will halt the main build.

So it seems to me that the appropriate course is to create a branch  
and work there; once the code is in place, people can try building on  
various systems; and once any build-halting problems have been  
addressed, we can merge the new material into the trunk.

Feedback/suggestions invited......... thanks.

JK