bug#15841: Display bugs with cache-long-lines non-nil

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Cc: 15841@debbugs.gnu.org,  nbtrap@nbtrap.com
> Date: Sun, 10 Nov 2013 19:20:13 +0100
> 
> Sorry, I was misguided.  What was slow wasn't `line-number-at-pos' but
> redisplay (so only the result of evaluation showed up delayed).  This
> long time for redisplay does only happen with some code I'm currently
> developing, but also only when cache-long-scans is non-nil.

Thanks for clarifying.

> Anyway, I'll tell you when I have a recipe.

Please do, and thanks.