Emacs 25.1 RC2 - sporadic display errors on Linux virtual terminal.

[Alan Mackenzie]

Hello, Emacs.

On the Emacs 25.1-rc2, I'm seeing worrying display anomalies on a Linux
virtual terminal.

My Emacs is configured with:

    ./configure  -with-gif=no --with-tiff=no --with-gpm

.

What I see is on full speed typing (I type at, perhaps, 10 characters
per second), a character fails to be displayed, the following character
takes its place, and a space is left afterwards.  For example, I just
now typed

    deal

.  This was displayed (in what is basically Text Mode) as

    da l

.  On typing C-l, the display becomes correct again.

It appears that Emacs goes into some sort of mode where this happens.  It
happened to me a few days ago (at the end of an hours long session), and
I just put it down to "one of these things".  It's just happened to me
again.  I am currently getting one of these errors, perhaps once every
two lines of typed text (where a line is ~78 characters).

Does anybody have any idea what might be happening?

-- 
Alan Mackenzie (Nuremberg, Germany).