Bug 388647

please provide the output of:
qdbus org.kde.KWin /KWin supportInformation

when the issue is present.

Created attachment 109725 [details]
Kwin

Here it is, thanks.

Version
=======
KWin version: 5.8.7
Qt Version: 5.6.2
Qt compile version: 5.6.2
XCB compile version: 1.11.1

Operation Mode: X11 only

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_INPUT: yes
HAVE_DRM: yes
HAVE_GBM: no
HAVE_X11_XCB: yes
HAVE_EPOXY_GLX: yes
HAVE_WAYLAND_EGL: no

X11
===
Vendor: The X.Org Foundation
Vendor Release: 11803000
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
DAMAGE: yes; Version: 0x11
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb
XFIXES: yes; Version: 0x50
SYNC: yes; Version: 0x31
GLX: yes; Version: 0x0

Decoration
==========
Plugin: org.kde.kwin.aurorae
Theme: __aurorae__svg__Breezemite_dark
Blur: 1
onAllDesktopsAvailable: true
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
decorationButtonsLeft: 2
decorationButtonsRight: 6, 3, 4, 5
borderSize: 4
gridUnit: 10
font: Roboto,10,-1,5,75,0,0,0,0,0
smallSpacing: 2
largeSpacing: 10

Options
=======
focusPolicy: 0
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
shadeHover: false
shadeHoverInterval: 250
separateScreenFocus: false
placement: 4
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
rollOverDesktops: true
focusStealingPreventionLevel: 0
legacyFullscreenSupport: false
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5015
operationMaxButtonRightClick: 5014
commandActiveTitlebar1: 0
commandActiveTitlebar2: 30
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 30
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 31
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777251
showGeometryTip: false
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
inactiveTabsSkipTaskbar: false
autogroupSimilarWindows: false
autogroupInForeground: true
compositingMode: 1
useCompositing: true
compositingInitialized: true
hiddenPreviews: 1
glSmoothScale: 2
colorCorrected: false
xrenderSmoothScale: false
maxFpsInterval: 16666666
refreshRate: 0
vBlankTime: 6000000
glStrictBinding: true
glStrictBindingFollowsDriver: true
glCoreProfile: false
glPreferBufferSwap: 101
glPlatformInterface: 1
windowsBlockCompositing: true

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
timeThreshold: 150
reActivateThreshold: 350
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Multi-Head: no
Active screen follows mouse:  yes
Number of Screens: 1

Screen 0:
---------
Name: eDP-1
Geometry: 0,0,1920x1080
Refresh Rate: 60.0079


Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 520 (Skylake GT2) 
OpenGL version string: 3.0 Mesa 17.0.5
OpenGL platform interface: GLX
OpenGL shading language version string: 1.30
Driver: Intel
GPU class: Unknown
OpenGL version: 3.0
GLSL version: 1.30
Mesa version: 17.0.5
X server version: 1.18.3
Linux kernel version: 4.4.104
Direct rendering: Requires strict binding: yes
GLSL shaders:  yes
Texture NPOT support:  yes
Virtual Machine:  no
OpenGL 2 Shaders are used
Painting blocks for vertical retrace:  no

Loaded Effects:
---------------
zoom
dimscreen
slidingpopups
kwin4_effect_login
slide
screenshot
kwin4_effect_windowaperture
minimizeanimation
kwin4_effect_translucency
flipswitch
desktopgrid
coverswitch
kwin4_effect_morphingpopups
kwin4_effect_maximize
kwin4_effect_fade
presentwindows
highlightwindow
kwin4_effect_dialogparent
blur
contrast
startupfeedback
screenedge
kscreen

Currently Active Effects:
-------------------------
blur
contrast

Effect Settings:
----------------
zoom:
zoomFactor: 1.2
mousePointer: 0
mouseTracking: 0
enableFocusTracking: false
followFocus: true
focusDelay: 350
moveFactor: 20
targetZoom: 1

dimscreen:

slidingpopups:
fadeInTime: 75
fadeOutTime: 125

kwin4_effect_login:

slide:

screenshot:

kwin4_effect_windowaperture:

minimizeanimation:

kwin4_effect_translucency:

flipswitch:
tabBox: false
tabBoxAlternative: false
duration: 100
angle: 30
xPosition: 0.33000001311302185
yPosition: 1
windowTitle: true

desktopgrid:
zoomDuration: 150
border: 10
desktopNameAlignment: 0
layoutMode: 0
customLayoutRows: 2
usePresentWindows: false

coverswitch:
animationDuration: 100
animateSwitch: true
animateStart: true
animateStop: true
reflection: true
windowTitle: true
zPosition: 900
primaryTabBox: false
secondaryTabBox: false

kwin4_effect_morphingpopups:

kwin4_effect_maximize:

kwin4_effect_fade:

presentwindows:
layoutMode: 0
showCaptions: true
showIcons: true
doNotCloseWindows: false
ignoreMinimized: true
accuracy: 20
fillGaps: true
fadeDuration: 75
showPanel: false
leftButtonWindow: 1
rightButtonWindow: 2
middleButtonWindow: 0
leftButtonDesktop: 2
middleButtonDesktop: 0
rightButtonDesktop: 0

highlightwindow:

kwin4_effect_dialogparent:

blur:
blurRadius: 12
cacheTexture: true

contrast:

startupfeedback:
type: 3

screenedge:

kscreen:

From support information everything looks fine. What about other global shortcuts? Are they still working? Any other where you notice differences?

Yes, I use quite a lot of shortcuts intensively and they all work well.

Only the second use of these gets ignored.

And just shortcuts of KWin or are also other applications affected?

Only kwin, no other shortcut.
I just noticed that if I plug the HDMI screen back, the shortcut works again.
And if I unplug it once more time, again stop working.

I realized that:

- after entering the desktop grid / windows views, the keyboard stops working. All keys are ignored: ESC to exit, arrows to select other windows or desktops, etc. So it is not only the shortcut like I stated in my first report.

- it can always been reproduced after unplugging the HDMI screen.

- if I re-plug the HDMI right after, without any things else, the keys are again magically recognized.

If it gets too messy, confusing, I can close this and reopen a new issue.
And if a video or something like that can help, let me know.

Fix in Qt 5.9.0 and KWin 5.10.3

See qtbase: 2b34aefcf02f09253473b096eb4faffd3e62b5f4
See KWin: a6dee74ee455d1da47dd5c9d55a84adbb5e1426a

The reason is that:
When the screen is disconnected, The QDesktopWidget will to delete the QDesktopScreenWidget object corresponding to the screen, which will cause QXcbConnection::removeWindowEventListener to be called, and the event corresponding to the root window will no longer be processed by QXcbConnection.

I'm sorry. Also need this commit of qtbase: d7a9e08f0ada36ad8ad44651f27a76c9c74e3428

(In reply to zccrs from comment #10)
> Fix in Qt 5.9.0 and KWin 5.10.3
> 
> See qtbase: 2b34aefcf02f09253473b096eb4faffd3e62b5f4
> See KWin: a6dee74ee455d1da47dd5c9d55a84adbb5e1426a
> 
> The reason is that:
> When the screen is disconnected, The QDesktopWidget will to delete the
> QDesktopScreenWidget object corresponding to the screen, which will cause
> QXcbConnection::removeWindowEventListener to be called, and the event
> corresponding to the root window will no longer be processed by
> QXcbConnection.