#635 WebKit not closed down properly?

[Christa Runge]

I see a lot of assertions and error messages in the console output, like:
2020-06-20 20:16:10.080849+0200 karatasi[61474:1586515] WF: _userSettingsForUser : (null)
2020-06-20 20:16:10.081011+0200 karatasi[61474:1586515] WF: _WebFilterIsActive returning: NO
2020-06-20 20:16:21.157280+0200 karatasi[61474:1586515] [ProcessSuspension] 0x1128f3b70 - ProcessAssertion::processAssertionWasInvalidated()
2020-06-20 20:16:51.032229+0200 karatasi[61474:1586515] Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service

These messages suggest that we don't shutdown the Web service properly.

[Christa Runge]

2020-07-18: at commit e48973, I still see error messages like:

2020-07-18 12:45:01.245427+0200 karatasi[85150:7577379] [ProcessSuspension] 0x10e5f34e0 - ProcessAssertion::processAssertionWasInvalidated()

2020-07-18 12:45:31.121643+0200 karatasi[85150:7577379] Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service

[Christa Runge]

I have displayed the numerical values for all currently documented WKErrorCode.
They have values between 1 and 11. No 113 here.

[Christa Runge]

Fixed error 113 at commit 0af116b143077891303f1aebe735ee0baebb29f2.
But I still see error messages like
[ProcessSuspension] 0x10c5f3720 - ProcessAssertion::processAssertionWasInvalidated()
and
[ProcessSuspension] 0x600002b00540 - WKProcessAssertionBackgroundTaskManager: Ignored request to start a new background task because the application is already in the background

Root cause of error 113 was that the WKWebView can load content only while it is included somewhere in the view hierarchy. This has implications on the correct initialisation order, but also on the correct shutdown order. Especially it is a good idea to stop any ongoing loading process before removing the view from the view hierarchy.