make-local-variable scrambles default value [lookup-syntax-properties garbled]

[stephen at xemacs.org]

Ilya N. Golubev writes:

 > xemacs branch: 21.4.

I can replicate this in CVS HEAD (post-21.5.27).

 > The code below does use `save-excursion' within `let' as adviced in
 > <(elisp) Intro to Buffer-Local>.  Still the assignment that one
 > expects to be temporary permanently breaks default
 > `parse-sexp-lookup-properties' value, and in a way that is hard to
 > detect.  It does not manifest right after the assignment, only after
 > `make-local-variable' is called.  That is, the following code

I have no idea what's going on here.  I'll pass it to the guys who
implement the Lisp engine, but I can't guess how long it will take to
solve.  So, this is our bug AFAICT, but a workaround at the
application level would be greatly appreciated. :-(

Steve