[winswitch] Odd behaviour in xpra

[Antoine Martin]

On 02/09/2021 23:21, Anthony Stone via shifter-users wrote:
> Hello,
> 
> I'm using xpra v4.2.2-r0 under Ubuntu 18.04 on both server and client. I
> find that sometimes, when I type a command, the response is just a blank
> line, with no command output and with the cursor left where the end of
> the new command prompt would be. Sometimes the command output and a new
> prompt appear after a pause, over-writing the original blank response.
> Hitting the return key causes them to appear anyway, with an extra prompt.
> 
> It's not a serious problem but it's a bit irritating.
I can imagine!
I have seen this bug in the past, but not recently.

OTOH, it could be a number of things:
* buggy screen updates that somehow don't end up on screen (ie: decoding
errors) - those normally cause error messages in your client's output or
in the server log - do you see any?
* buggy display drivers / display code - turning off or forcing on the
OpenGL acceleration from the system tray may fix that. Terminals should
be detected as 'text' applications and therefore not using OpenGL.

To debug, you can try a few things:
* the "F10" shortcut to toggle paint debugging (on most Linux desktops,
that's "Ctrl+Shift+F10" over the window) - the colours should then
indicate how it's trying to update the screen,
* turning off specific encodings, ie: --encodings=jpeg,rgb,webp
and hope to isolate the buggy one
* the "refresh window" entry from the tray menu, does this "fix" things?
This may give us some clues as to what is going on.

Creating a ticket may be the best way to get this resolved:
https://github.com/Xpra-org/xpra/issues/new/choose

Cheers,
Antoine

> 
> Anthony