slowness scrolling in *Help* windows

[Perry E. Metzger]

Running a recent version of the trunk I've compiled on Mac OS X

(aka GNU Emacs 24.4.50.1 (x86_64-apple-darwin13.3.0, NS
appkit-1265.21 Version 10.9.4 (Build 13E28)) of 2014-09-04 on
jabberwock.cb.piermont.com)

I've been noticing that sometimes scrolling in *Help* gets very, very
slow sometimes. Typical case: C-h s (that is, view the syntax table),
and scroll through it, and it can take seconds for the screen to do
something after C-v

It is possible this is only happening if there are loads of "unusual"
Unicode characters in the buffer in question. I don't have any good
very long files of lots of Unicode characters to check if it is
happening on all buffers, or just *Help* buffers.

Is this a known problem? Should I file a bug report?

-- 
Perry E. Metzger                address@hidden