bug#50462: 27.2; emacsclient syntax highlight failure

[Eli Zaretskii]

> From: RDS <rds1944@gmail.com>
> Date: Tue, 7 Sep 2021 11:11:20 -0700
> 
> Initially everything behaves as expected in console & X. Then on time scales 
> ranging from minutes to hours
> with the various emacsclients, randomly switching among tty's & killing / 
> loading buffers, I eventually see
> that .bashrc is displayed with "missing" chars.

Are they really missing, or just displayed with the same foreground
and background colors?  What happens if you move the cursor (with C-f
or C-b) across the "missing" text?

Also, do you see any error messages in the *Messages* buffer when this
happens?