Re: merge emacs-bidi into the main tree

    > IIRC, you were worried about the performance hit: the code as written
    > in the display engine part required to disable all the optimizations
    > and shortcuts that exist for the left-to-right languages, 

Does it disable the optimizations always, or only when there is
right-to-left text?

								and you felt
    > this would hamper redisplay performance even in the simplest cases,
    > like cursor motion and insertion of a single character.

    Yes, that matches the little I remember.

If the optimizations are disabled only when there is right-to-left text,
and if the users of emacs-bidi think it is better than nothing, we may
as well include the feature anyway.

If the change requires disabling optimizations always, even for people
who don't use right-to-left text, that is potentially a serious
problem.  Maybe it can be solved by adding a flag that people must set
in order to use right-to-left text.  Of course, an automatic solution
would be better, but the flag would be enough to make it acceptable.