Re: Buffer corruption when the terminal is resized.

[Paul Peet]

I guess this is why I don't get the garbage output with gnome-terminal
and dash. Dash doesn't use readline apparently.

So, what can be done to actually fix this?

On Mon, Jun 12, 2017 at 7:55 PM, Chet Ramey <chet.ramey@case.edu> wrote:
> On 6/12/17 1:38 PM, Paul Peet wrote:
>> Uhmm, I am not sure how to interpret these results (All shells or
>> terminals have been tested with Ubuntu 17.04):
>>
>> gnome-terminal + bash: Happens
>> gnome-terminal + zsh: This bug also happens here, lines are getting
>> removed/repeated...
>> gnome-terminal + dash: Does not happen. (I changed the
>> PS1="username@hostname $" to make it longer)
>> gnome-terminal + mksh: The bug also occured here. Same as bash and zsh.
>
> I suspect this happens due to mismatched expectations. The cases with
> garbled output seem to occur where the redisplay engine assumes the
> terminal maintains the text across resizes (so it can do intelligent
> redisplay using what's already on the screen) and the terminal emulator
> assumes the foreground process is going to take care of doing all the
> redisplay after a SIGWINCH and doesn't bother with the screen contents.
>
> The readline redisplay engine assumes that the only characters on the
> screen are those it writes.  If that assumption is violated on a size
> change, you'll get indeterminate results.
>
> --
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                  ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, UTech, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/