[Bug: 21.5-b27] Hang when writing.

[Stephen J. Turnbull]

Aidan Kehoe writes:
 > ================================================================
 > Dear Bug Team!
 > 
 > This XEmacs occasionally hangs when saving files. Here’s a backtrace from
 > the most recent incident: 

This is probably due to some fiddling that Jerry and Tony Bennett @
nvidia (IIRC) did with lstream flushing to fix a different timing bug.
Or it might be due to a commit I made (also originally from Tony) to
cut down the initial timeout when waiting for a stuffed pipe to clear,
and gradually lengthen it.

I'll be working on the archives later today, but there won't be search
yet.:-(