Linux : GFX_FULLSCREEN + GFX_OPENGL steals keyboard input from all other windows

[clebercasali]

Starting fullscreen (GFX_FULLSCREEN) in opengl mode (GFX_OPENGL) will cause the program to steal keyboard input from all other windows.
Can do ALT+ENTER, but can't ALT+TAB, can't type...

[code]
dim as integer fullscreen=1, useopengl=1, gfxnoswitch=0, borderlesswindow=0, alwaysontop=0, alphaprimitives=0, highpriority=0, multisample=0

dim as long screenflags=iif(fullscreen,&h01,0) or iif(useopengl,&h02,0) or iif(gfxnoswitch,&h04,0) or iif(borderlesswindow,&h08,0) or iif(alwaysontop,&h20,0) or iif(alphaprimitives,&h40,0) or iif(highpriority,&h80,0) or iif(multisample,&h40000,0)
screenres 1920, 1080, 32, 1, screenflags, 60

do
screensync
flip
loop until multikey(1)
[/code]

I think this behaviour was introduced trying to fix another bug (freeze on start).

[clebercasali]

I think this is related:
https://www.freebasic.net/forum/viewtopic.php?t=12587
https://www.freebasic.net/forum/viewtopic.php?t=12287