Profile corruption when using QWebEnginePage together with WebEngineView



  • I have a desktop application at work that apparently uses both QWebEnginePage to generate a license agreement page as well as two WebEngineView qml components to display some banners in a launcher.

    Running the application in debug resulted in an instant crash with an unhandled exception seemingly originating from the Chromium backend. The output log is consistent with: https://bugreports.qt.io/browse/QTBUG-59244.
    Running with the debugger attached it seems that its possible to step over the error and execution continues seemingly unaffected.

    While investigating, I noticed that if I commented out the qml WebEngineView components, everything worked.
    Deleting the "default" profile in %CURRENTUSER%\AppData\Local<AppName>\QWebEngine seems to have fixed it. Unfortunately I can no longer replicate the issue since doing this.

    Now, investigating this bug was actually a detour from my original task as such I'm afraid I cannot dig deeper but I am curious to understand more about what might've happened.

    The only hypothesis I came up with is that the "default" profile is probably used by both the QWebEnginePage object and the WebEngineView component and this caused some sort of corruption in the profile.

    Does this sound likely?
    If yes, would creating a profile for the qml components and another profile for the QWebEnginePage object reduce the chances of profile corruption?

    These are more theoretical questions really because, like I said, I'm afraid I no longer have the time to dig further into this, especially since so far there haven't been other similar incidents reported.