bug#34179: 27.0.50; message hangs when buffer with process visible

[Michael Heerdegen]

Hello,

I don't have a recipe, and I'm not sure it's not my fault.  This started
to happen since about two or three weeks ago where I always used a quite
recent master built.

The problem is: when some Emacs frame is displaying *shell*, or, I
think, some other buffer having an attached buffer process, Emacs
randomly freezes: 100% CPU usage, nothing happens, need to hit C-g
several times to get out.

With debug-on-quit on I see that the backtrace is quite different every
time, different situations, but they have all in common that 'message'
is at the top (i.e. has been interrupted by C-g).

With the profiler I also see that message has been run for a very long
time (not redisplay, that has a much smaller amount).

When I close the frame displaying *shell* the problem goes away.

I tried to find a culprit in my init file but without success so far.


Thanks,

Michael.


In GNU Emacs 27.0.50 (build 34, x86_64-pc-linux-gnu, GTK+ Version 3.24.3)
 of 2019-01-22 built on drachen
Repository revision: b926c8dbb777b8a710327cdb184bb260e3fbb511
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description: Debian GNU/Linux buster/sid