Re: Calling Lisp from undo.c's record_* functions

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> When would it not be called?
> E.g., in insert_from_gap.  Also, in many insdel.c functions when they
> are called with the PREPARE argument false.

AFAIK these are cases where prepare_to_modify_buffer has already been
called earlier.

>> You mean there are cases where we'd add stuff to the undo list but
>> we don't run before-change-functions?
> I don't know.  I don't think we have such bugs, but thinking is one
> thing and convincing yourself it's true by looking at the callers is
> something entirely different...

That's OK, then: I believe that failing to call run_undoable_change is
not more serious than failing to run before-change-functions.

So I think moving the call to run_undoable_change into
prepare_to_modify_buffer is n attractive solution to this problem, since
it preserves the use of Elisp, and it probably also simplifies the code
(since we can remove most/all other calls to run_undoable_change).


        Stefan