Browser hangs after adding 24 tabs

[lluke777]

qutebrowser v1.4.0
Git commit: 0f037fb (2018-07-03 15:44:44 +0200)
Backend: QtWebEngine (Chromium 65.0.3325.230)

CPython: 3.6.5
Qt: 5.11.1
PyQt: 5.11.2
Windows 7 64bit

After fast adding 24 tabs there is no response from browser.

[The-Compiler]

How can I reproduce this?

[The-Compiler]

Hmm, I can actually reproduce this by opening some more tabs - it seems like some bug in Qt, though.

[lluke777]

24 x Ctrl+t 😄

[kmorihiro]

:set qt.force_software_rendering chromium avoids this issue in my environment.

qutebrowser v1.5.2
Git commit: a42f37a (2018-10-26 10:20:24 +0200)
Backend: QtWebEngine (Chromium 65.0.3325.230)

Style: QWindowsVistaStyle
Platform: Windows-10-10.0.16299-SP0, 64bit
Frozen: True
Imported from C:\Program Files\qutebrowser\qutebrowser
Using Python from C:\Program Files\qutebrowser\qutebrowser.exe
Qt library executable path: C:/Program Files/qutebrowser/PyQt5/Qt/bin, data path: C:/Program Files/qutebrowser/PyQt5/Qt
OS Version: 10, 10.0.16299, SP0, Multiprocessor Free

GPU: AMD Radeon R7 200 Series

[The-Compiler]

Also see #5586 - according to @mikeyww there's still an issue when opening more tabs:

Failed to create OpenGL context for format

QSurfaceFormat(version 2-0, options
QFlagsQSurfaceFormatz:FormatOption(), depthBufferSize 24,
redBufferSize -1, greenBufferSize -1, blueBufferSize -1,
alphaBufferSize -1, stencilBufferSize 8, samples 0, swapBehavior
QSurfaceFormat::DefaultSwapBehavior, swaplnterval 1,
colorSpace QSurfaceFormat::DefaultColorSpace, profile
QSurfaceFormat22NoProfile) .
This is most likely caused by not having the necessary graphics
drivers installed.

Install a driver providing OpenGL 2-0 or higher, or, if this is not
possible, make sure the ANGLE Open GL ES 2.0 emulation
libraries (libEGL.dll, libGLESv2-dll and d3dcompiler_*.dll) are
available in the application executable's directory or in a location
listed in PATH.

Batch script from there:

@echo off
TITLE Qutebrowser crash
REM -----------------------------------------------
REM This Windows batch program will crash qutebrowser.
REM -----------------------------------------------
SET n=0
SET browser="%ProgramW6432%\qutebrowser\qutebrowser.exe"
echo:
REM -----------------------------------------------
SET url[1]=http://www.amazon.com/
SET url[2]=http://www.dell.com/
SET url[3]=http://www.microsoft.com/
SET url[4]=http://www.hp.com/
SET url[5]=http://www.google.com/
SET url[6]=http://www.nbc.com/
SET url[7]=http://www.cbs.com/
SET url[8]=http://www.abc.com/
SET url[9]=http://www.aa.com/
SET url[10]=http://www.united.com/
SET url[11]=http://www.delta.com/
SET url[12]=http://www.epson.com/
SET url[13]=http://www.hp.com/
REM -----------------------------------------------
setlocal enabledelayedexpansion
REM -----------------------------------------------
:loop
SET /A n += 1
IF NOT DEFINED url[%n%] GOTO :done
echo %n%. Opening: !url[%n%]!
START "Browse" %browser% !url[%n%]!
TIMEOUT /T 1 >NUL
GOTO :loop
REM -----------------------------------------------
:done
echo:
Pause
EXIT

[The-Compiler]

Could someone who's affected (e.g. @mikeyww) check if you get the same problem with KDE Falkon as well?

FWIW I just tried to reproduce this again in qutebrowser with my Windows 10 VM, and I can't reproduce it anymore, even with some 50 tabs.

[mikeyww]

I tried Falkon and received the same crash and error message after about five tabs.

[The-Compiler]

Definitely an upstream issue in Qt then. I first thought it could be Windows 7 specific, but apparently @kmorihiro saw it on Windows 10 above as well? Can someone still reproduce this on Windows 10 with an up-to-date Qt/qutebrowser?

[mikeyww]

FYI: From Mali_OpenGL_ES_Emulator-v3.0.4-2-g8d905-Windows-64bit.zip, I copied the following files into qutebrowser's directory.

• libEGL.dll
• libEGL.lib
• libGLESv2.dll
• libGLESv2.lib
• libMaliEmulator.dll
• libMaliEmulator.lib
• log4cplus.dll

This did not help. The crash still occurred after about 19 tabs.