bug#37620: 26.1; ada-mode 6.2.1 partial parsing occasionally hangs while moving point

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

No, the machine is not particularly loaded.  I believe the most
likely cause is "the code has a syntax error that is particularly
hard to correct"; but this is only because of partial parsing as
the entire file is syntactically correct.

I'll send you the next source file where this happens; maybe
you can reproduce.

Increasing wisi-process-time-out to more than 5 seconds does not
seem like a solution to me; parsing the entire buffer (resulting in
no syntax errors, no attempted recovery and no time-out) takes
less than that.  Also, since we are only moving point in an
unmodified buffer, interactive use requires 0.1 s response time or
less.  Therefore, perhaps a solution would be to /decrease/
wisi-process-time-out and automatically launch a full parse
whenever it happens; as long as the buffer remains unmodified, no
re-parsing will take place.

-- 
Ludovic Brenta.