Release plans

[Stephen J. Turnbull]

Michael Sperber writes:
 > >             if setq custom-file is found:
 > >                 disable it
 > 
 > That is precisely *not* leaving it alone.  (The problem is that "finding
 > setq custom-file" is undecidable.)

So is pretty much everything else about migration, although not in the
technical sense I presume you mean -- XEmacs cannot know which forms
the user "really" wants migrated.  However, this case is easy enough:
run xemacs in a separate process, load the .emacs we've found
explicitly, and find out what value custom-file has.  If we can't
figure out where it was set, we can append a setq to init.el to force
an XEmacs-specific custom file.  If the user is writing the custom
file from the init file, we're screwed of course, but that's perverse.

I think we can limit this paranoia to the init file and custom.el, but
on the other hand we know for sure that XEmacs will screw up those two
files (or perhaps choke on them).