[Spice-devel] [PATCH spice-gtk 2/4] main: send only pending monitor config changes

[Marc-André Lureau]

Hi

----- Original Message -----
> On Fri, 2015-04-03 at 11:25 -0400, Marc-André Lureau wrote:
> Oh, I just thought of one potential example (note that I haven't
> actually tested it with your patches):
> 
> - User connects a fullscreen (1600x900) virt-viewer to a guest
> - user reboots guest
> - during reboot, guest switches to e.g. 720x400 (which results in a
> scaled display widget in the fullscreen window)
> - There is no vdagent running during boot
> - The graphical login screen (gdm) comes up and vdagent connects
> - the gdm greeter will default to e.g. 1024x768
> - There are no pending monitor changes, so your patch prevents us from
> sending a monitors config message to the server
> 
> Result: the gdm greeter is a 1024x768 widget scaled up to a fullscreen
> 1600x900 window. In other words, it is zoomed in, "fuzzy", and with
> black bars along the sides.
> 
> Previously, we would have unconditionally sent a monitors config update
> to the server when the vdagent became connected, which would have
> resulted in the gdm screen being configured to the fullscreen window
> size.

If auto-resize is disabled, we shouldn't send monitor config messages: this is a bug we have currently.

If it's enabled, this patch shouldn't break current behaviour.

> This is just one example off the top of my head, but I'm sure there are
> several other scenarios that I can't think of immediately (VT switching?
> vdagent restarting?).
> 
> As I said in my previous email, I think that if we change this behavior,
> it would probably be better to remove it completely and leave it up to
> the application to handle.

This is not possible unless you implement the behaviour in all existing applications. What you want is a way to prevent sending those unwanted configuration messages, which is what these series help with.