Disable local screensaver when x2go session is in fullscreen mode

[sunweaver]

From X2Go BTS:
http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=554

Package: nxproxy
Severity: serious

I noticed that the when nxproxy is in fullscreen mode, it (by design)
captures all keyboard strokes. This is in general great because this
way all keyboard shortcuts on the remote work.

However, the local screen saver might still kick in and require a
password. Because the nxproxy captures all input, a less carefull user
might enter his local password into the current application that is
running in the x2go session. When the remote application happens to be
a chat application, entering your password might have serious security
implications.

I think a fullscreen nxproxy is a good reason to inhibit the local screensaver.

[sunweaver]

I just found that the screensaver gets disabled when nxagent is launched in fullscreen mode:
https://github.com/ArcticaProject/nx-libs/blob/3.6.x/nx-X11/programs/Xserver/hw/nxagent/Screen.c#L1442

However, it may well be that this actually fails.

Furthermore, it is well possible, that the re-enable/re-disable mechanism is not working / not implemented, but should be.

[uli42]

Most aspects of screensaving seem to be broken, see also #263 and #80

[uli42]

I have a fullscreen session. Screenblanking on the native display is disabled (xset q reports a timeout of 0. Activating the screen blanker there by calling xset s 10 results in a blank screen after 10s, and pressing any key unblanks the screen again. I am wondering how the original problem you describe might happen.

[uli42]

I just saw that the local screensaver is disabled in Window.c/nxagentSwitchAllScreens(), too