bug#3208: 23.0.93; Memory full / crash when displaying lots of characters from a large font (like Arial Unicode or Code2000) which is not explicitly selected (on Win32)

[Jason Rumney]

Kenichi Handa wrote:
> Although I still can't reproduce the problem (except for the
> very slowness redisplay), I noticed some inefficiency in
> fontset_font.  So, I've installed an improvement in the
> TRUNK.  As a result, in the case of inserting many #x2203,
> the redisplay got faster.
>   

The memory full problem is still there. I am surprised you don't see it 
if you are seeing the slowness, since if things were working correctly, 
only the first character displayed should be slow while the fonts are 
searched, subsequent insertion of the same character should reuse the 
cached font.

Your change seems to have reduced the first time display of etc/HELLO 
from 12 seconds for the uniscribe backend to 10 seconds, vs 2 seconds 
for the gdi backend and Emacs 22 (though only uniscribe can display the 
complex scripts correctly). Subsequent redisplays are near 
instantaneous, so it still seems to be searching for fonts rather than 
displaying them that takes the time.