bug#29817: 26.0.50; Saving files on remotes very slow if shell buffer is open

[Vitalie Spinu]

Hi,

I am observing a rather weird interaction between tramp and comint. Saving and
editing files on remotes is pretty snappy till I open a shell buffer. Once a
shell is open it can take good 10s to save a buffer. Editing and navigation are
also impaired.

Steps to reproduce:

  1) emacs -Q
  2) /ssh:remote-host:tmp.txt
  3) save tmp.txt (snappy)
  4) M-x shell
  5) back to tmp.txt and save (terribly slow)

Can anyone reproduce this?

  Vitalie

In GNU Emacs 26.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.18.9) of 
2017-12-22 built on galago
Repository revision: 5d45ba1a05bccc53d52422e867f378a0adeb8970
Windowing system distributor 'The X.Org Foundation', version 11.0.11804000
System Description:     Ubuntu 16.04.2 LTS