Details
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Bug
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Resolution: Done
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P2: Important
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5.12.0, 5.12.1
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None
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Windows 7x64, Qt 5.12.0, MSVC2017 32bit
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Windows
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56fadb571f32b721d8b99554e6e38692009ec37f
Description
I have a qml file with a QWebView (the one from qml). It is loaded with a QQuickWidget that itself is contained inside a subclassed QWidget.
Quitting the application fails with an error.
This can be reproduced with the attached example.
—
Update 24.02.: I figured out a workaround. It ensures that all QWidgets which contain a QQuickWidget (with a QWebView) are destroyed before quitting the application. Somehow I cannot upload another file so I added the code at the end of this post.
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In the example I tested different combinations:
The error occurs, if:
- The qml is created inside the constructor of the widget, or later passed as a pointer AND
- The QWebView must have loaded content (either via "url"-parameter or via "loadHTML"), before quitting the app
The error does not occur, if I create the QQuickWidget in main() and pass it by reference to the QWidget. But that is probably some side effect, The main issue seems to be with deletion of the context, I guess.
Debug output is
{{}}
[11328:19036:0223/150952.613:FATAL:render_process_host_impl.cc(887)] Check failed: map_.empty()
{{}}
I found a post with the same error message, see answer from "yan12125"
https://github.com/nextcloud/desktop/issues/941
which was solved by a patch that corrects the deallocation order:
https://github.com/electron/electron/pull/15028
The complete stacktrace is
{{}}
[11328:19036:0223/150952.613:FATAL:render_process_host_impl.cc(887)] Check failed: map_.empty(). Backtrace: QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11B4E857+810583] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11B5BD11+865041] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11A93A9E+45214] QtWebEngineCore::JavaScriptDialogController::qt_static_metacall [0x1166ED0A+32480538] QtWebEngineCore::JavaScriptDialogController::qt_static_metacall [0x1167185F+32491631] GetHandleVerifier [0x12ED8CE9+20263193] IsSandboxedProcess [0x1403328B+16485723] IsSandboxedProcess [0x13A93802+10588882] IsSandboxedProcess [0x1406445F+16686895] IsSandboxedProcess [0x14063EDD+16685485] QtWebEngineCore::JavaScriptDialogController::qt_static_metacall [0x10406C6D+13180029] QtWebEngineCore::JavaScriptDialogController::qt_static_metacall [0x10406C41+13179985] IsSandboxedProcess [0x13D95555+13742117] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11AC020E+227342] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11AC0148+227144] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11ABF94F+225103] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11ABF96F+225135] QWebEngineUrlSchemeHandler::_q_destroyedUrlSchemeHandler [0x11ABFA2C+225324] QtWebEngineCore::JavaScriptDialogController::qt_static_metacall [0x1115CC69+27163769] QtWebEngineCore::ProfileAdapterClient::downloadInterruptReasonToString [0x0F70855F+2623] QtWebEngineCore::ProfileAdapterClient::downloadInterruptReasonToString [0x0F7086A6+2950] QtWebEngineCore::ProfileAdapterClient::downloadInterruptReasonToString [0x0F70888F+3439] QtWebEngineCore::ProfileAdapter::checkPermission [0x0F705B56+230] QtWebEngineCore::FilePickerController::mode [0x0F71EDBA+33066] QtWebEngineCore::ProfileAdapter::~ProfileAdapter [0x0F7054E6+246] QtWebEngineCore::ProfileAdapter::~ProfileAdapter [0x0F7055DD+493] QtWebEngineCore::WebEngineSettings::setWebContentsAdapter [0x0F69BCEA+3418] QtWebEngineCore::WebContentsAdapter::requestedUrl [0x0F741E5A+746] QWebEngineUrlScheme::operator!= [0x0F74BB8B+3707] QWebEngineUrlScheme::operator!= [0x0F74BCB7+4007] QTextCodec::codecForHtml [0x5F98A3C2+3390559] QTreeViewPrivate::layout [0x609525D6+456449] main [0x001F6D24+628] (d:\anonymous\qml-user-js-crash\userjs\main.cpp:67) WinMain [0x001F664D+173] (c:\users\qt\work\qt\qtbase\src\winmain\qtmain_win.cpp:104) invoke_main [0x001F50AE+30] (d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:107) __scrt_common_main_seh [0x001F4F47+343] (d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288) __scrt_common_main [0x001F4DDD+13] (d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:331) WinMainCRTStartup [0x001F5128+8] (d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_winmain.cpp:17) BaseThreadInitThunk [0x7694343D+18] RtlInitializeExceptionChain [0x776A9802+99] RtlInitializeExceptionChain [0x776A97D5+54]
{{}}
Workaround code:
workaround.h
#ifndef WORKAROUND_H #define WORKAROUND_H #include <QPointer> // QT-BUG https://bugreports.qt.io/browse/QTBUG-74021 class Viewer; class ViewerCleanupRegistry{ ViewerCleanupRegistry(){} QList<QPointer<Viewer> > viewers_; public: ViewerCleanupRegistry(const ViewerCleanupRegistry &other) = delete; void operator=(const ViewerCleanupRegistry &other) = delete; void registerViewer(Viewer *v); static ViewerCleanupRegistry& instance(); void cleanup(); }; #endif // WORKAROUND_H
workaround.cpp
#include "workaround.h" #include "viewer.h" ViewerCleanupRegistry &ViewerCleanupRegistry::instance(){ static ViewerCleanupRegistry v; return v; } void ViewerCleanupRegistry::cleanup(){ for ( auto &v : viewers_ ){ if (v.isNull()){ viewers_.removeOne(v); }else{ const_cast<Viewer *>(v.data())->deleteLater(); viewers_.removeOne(v); } } } void ViewerCleanupRegistry::registerViewer(Viewer *v){ viewers_.append(QPointer<Viewer>(v)); }
In the Constructor of Viewer, call
ViewerCleanupRegistry::instance().registerViewer(this);
Then quit the app like this and no crash occurs:
trayMenu.addAction("Exit",[&](){
ViewerCleanupRegistry::instance().cleanup();
qApp->quit();
});
Attachments
| For Gerrit Dashboard: QTBUG-74021 | ||||||
|---|---|---|---|---|---|---|
| # | Subject | Branch | Project | Status | CR | V |
| 254596,8 | Force destruction of webcontent client before profile adapter | 5.12 | qt/qtwebengine | Status: MERGED | +2 | 0 |