Subject: Bug#1074: Firefox browser window "twitches" during page load

From: Stefan Baur <[email-masked]>
Date: Sat, 20 Aug 2016 16:07:37 +0200

package: x2goclient
version: 4.0.5.1-2016.06.05
tag: X2GoGathering2016

Note: Only noticed on MS Windows so far
 Steps to reproduce:
- Run Firefox in PubApp mode
- Maximize the Firefox window
- Enter a URL like http://slashdot.org in the URL bar and hit "Enter"
Window should "twitch" by a few pixels before returning to original size
- Enter a second URL like http://soylentnews.org the same way
Window should twitch again

Notes
- Happens even with all JavaScript disabled, so cannot be a JavaScript issue
- Does not happen when Window isn't in fullscreen mode

Server is Debian Jessie 8.5, Firefox is Firefox ESR 45.2.0

dpkg -l|egrep "x2go|nx"
ii  cups-x2go
3.0.1.3-0x2go1+git20160614.135+jessie.main.1    all          Virtual
X2Go printer for CUPS
rc  freenx-media                          0.7.3+teambzr104-0freenxteam1
                 amd64        Remote desktop/application/thin-client
server media support
rc  freenx-smb
0.7.3+teambzr104-0ubuntu1~karmic1               amd64        Remote
desktop/application/thin-client server smb support
ii  libnx-x11-6:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
client-side library
ii  libnx-xcomposite1:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
Composite extension library
ii  libnx-xdamage1:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
damaged region extension library
ii  libnx-xdmcp6:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
Display Manager Control Protocol library
ii  libnx-xext6:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
miscellaneous extension library
ii  libnx-xfixes3:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
miscellaneous 'fixes' extension library
ii  libnx-xinerama1:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
Xinerama extension library
ii  libnx-xpm4:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
pixmap library
ii  libnx-xrandr2:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
RandR extension library
ii  libnx-xrender1:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
Rendering Extension client library
ii  libnx-xtst6:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
Testing -- Record extension library
ii  libxcomp3:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
compression library
ii  libxcompext3:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
protocol compression extensions library
ii  libxcompshad3:amd64
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        nx-X11
shadowing library
ii  nx-x11-common
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 all          nx-X11
(common files)
ii  nxagent
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        NX agent
ii  nxproxy
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 amd64        NX proxy
ii  x2go-keyring
2012.07.23+wheezy~main~17~build1                all          GnuPG keys
of all X2Go developers and the X2Go archive
ii  x2goagent
2:3.5.0.32-0x2go1+git20160614.734+jessie.main.1 all          X2Go agent
ii  x2goclient
4.0.5.1-0x2go1+git20160619.1180+jessie.main.1   amd64        X2Go Client
application (Qt4)
ii  x2godesktopsharing
3.1.1.3-0x2go1+git20160620.178+jessie.main.1    amd64        Share X11
desktops with other users via X2Go
ii  x2goserver
4.0.1.19-0x2go2+git20160621.1064+jessie.main.1  amd64        X2Go server
daemon scripts
ii  x2goserver-extensions
4.0.1.19-0x2go2+git20160621.1064+jessie.main.1  all          X2Go server
daemon scripts (extensions)
ii  x2goserver-xsession
4.0.1.19-0x2go2+git20160621.1064+jessie.main.1  all          X2Go server
daemon scripts (Xsession runner)

-Stefan

-- 
BAUR-ITCS UG (haftungsbeschränkt)
Geschäftsführer: Stefan Baur
Eichenäckerweg 10, 89081 Ulm | Registergericht Ulm, HRB 724364
Fon/Fax 0731 40 34 66-36/-35 | USt-IdNr.: DE268653243

---

From: Stefan Baur <[email-masked]>
Date: Sat, 20 Aug 2016 17:25:29 +0200

This does not happen when executed like this:

vcxsrv.exe -multiwindow #on windows
putty with X forwarding to :0 #on windows
firefox-esr # within putty on linux

So it is likely the bug is somewhere in the X2Go/NX-Libs components.

-Stefan