Qt 5.6 WebEngine problem with custom FlashPLayer locations

ThatDud3

According to Qt 5.6 › Qt WebEngine › Qt WebEngine Platform Notes › Adobe Flash Player Plugin Support (section) :

You can also load the Flash player from a specific location by using command line arguments:

--ppapi-flash-path=./libpepflashplayer.so

...but it is not working.

Suggestion in the first paragraph works though:
"The Adobe Flash player plugin can be loaded automatically if it is installed in one of the following locations, depending on the platform:"
If I copy to default path (that is also searched by WebEngine it works...

I mean using custom path works if I do it from command line too like:

app.exe --ppapi-flash-path=./pepflashplayer.dll

but it is not working when I do it in code like:

QApplication a(argc, my_argv);
qDebug() << "my_argv: " << qApp->arguments(); // ("C:\\temp\\app.exe", "--ppapi-flash-path=./pepflashplayer.dll")

so my_argv should be passed down to WebEngine but not honored
Is this a known bug in WebEngine...

ThatDud3

I've found a few similar bugs but they are all fixed...
https://bugreports.qt.io/browse/QTBUG-30330
https://bugreports.qt.io/browse/QTBUG-47023
https://codereview.qt-project.org/#/c/105750/

The only possibility left is that Chromuim doesn't use QApplication's argv and relies on arguments retrieved by GetCommandLine()
My question is - is this a bug or it is by design and what is the point of having qApp->arguments() if they aren't passed to QWebEngine?

ThatDud3

I opened a bug report QTBUG-51971