Re: Performance degradation from long lines

[Stefan Kangas]

Eli Zaretskii <address@hidden> writes:

> One comment I have is that disabling bidi-display-reordering should
> probably be removed from the defaults, because doing so puts the
> display engine in a state that is not being tested, and can cause
> inconsistencies and even bugs (because some portions of the code were
> written under the assumption that this variable is never nil).

I think some users are already setting bidi-display-reordering to nil.  I
stumbled into this the other day, for example:

    You can try and see if setting bidi-display-reordering to nil
improves the speed
    for you. This removes one significant contributor to line scans,
but sadly not
    the only one.

https://emacs.stackexchange.com/questions/598/how-do-i-prevent-extremely-long-lines-making-emacs-slow

Should Emacs support that?  Should it be added to its doc string that it could
be dangerous?

Thanks,
Stefan Kangas