redisplay issues

[Aidan Kehoe]

 Ar an triú lá déag de mí Meitheamh, scríobh Julian Bradfield: 

 > Switching from 21.4.20 to 21.5.28, I notice numerous small breakages
 > in my VM session (running the same VM code (slightly patched 7.19) in
 > both cases).
 > Some of them I have some chance of hunting down (point being
 > mispositioned in the summary buffer, for example), but some not.
 > 
 > In particularly, redisplay seems very flickery. Frames with multiple
 > windows flicker every time certain changes are made to the buffers
 > (I can't be precise yet about what causes obvious flickers), and in
 > some operations the frame goes blank for a noticeable period while
 > XEmacs is doing some computation.
 > In general, it looks as if redisplay is happening when it ought to be
 > held off to wait for some change to complete, and then optimized.

The main context where I’ve seen flicker with VM and redisplay has been with
interpretation of MIME character sets. decode-coding-region, which VM’s MIME
support ultimately calls, deletes the region, appears to do a redisplay, and
inserts the modified region. If you’ve been using a non-Mule 21.4, and
switched to a non-Mule 21.5, it may be that VM is using the basic coding
system support in non-Mule, and this flicker is suddenly appearing for you,
though I haven’t confirmed this locally. 

 > Is this a recognized issue with 21.5? I've found no obvious reference
 > to it, though I haven't searched extensively.

-- 
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more into contact with civilization, Dobrinton was bitten by a dog which was
assumed to be mad, though it may only have been indiscriminating. (Saki)