The removed lines were added by you a few minutes earlier. I did a full cvs update, ran autoconf and autoheader, and checked in the resulting files (after testing everything first).
AFAIK, pyconfig.h.in is a generated file, written by autoheader, so those #defines that you added won't stick. I'm not sure where they *should* go though.
Thanks for the notice. The right place is acconfig.h, which is the template for autoheader (autoheader also requires to put template definitions in there if it cannot determine the comment above itself). I've now corrected that.
I think there are a few places in configure.in where -D options are added to OPT or to CC -- I'm not sure why, it could be that the author of the patch didn't know the proper way, or it could be there was a special reason.
I guess it's both. Getting rid of -DINET6 is still on my agenda. In some cases, people apparently don't trust that pyconfig.h is always included before any system header. If that is guaranteed, I cannot think of any further special reason, unless there is some compiler that treats -D special (beyond defining the symbol). Regards, Martin