opening accounts then pressing back causes black screen

[Dave Morley]

If you open online accounts from settings and then hit back on the accounts page the application window goes black.

If you then right swipe between apps until you get back to the black window you will crash unity8 with the d8f8 crasher.

[Alberto Mardegan (mardy)]

Thanks Dave for reporting this! But I'd say that it's more a unity8 bug, than a bug in u-s-s-o-a. So I'm adding unity8 to this bug, while keeping u-s-s-o-a in the loop just in case there's something we can do to prevent this.

[Michał Sawicz (saviq)]

Also adding unity-mir, as it's somewhere around app management code. Trying to get a trace.

[Michał Sawicz (saviq)]

I actually was unable to reproduce this with the latest image and Qt 5.2, can you please see if that helps for you as well?

Especially when you mention the d8f8 crash, that's the 5.0-specific one, wasn't it?

[David Barth (dbarth)]

Unity8 is probably not crashing.

[Bill Filler (bfiller)]

running image 51 and this bug still exists.

unity8 is not crashing. Launching accounts from the system settings spawns this process:
/usr/bin/online-accounts-ui --desktop_file_hint=/usr/share/applications/online-accounts-ui.desktop

When pressing the back button, the window is closed but the process remains alive for a while and maybe this is causing the problem? I would imagine that is a unity-mir/window management bug

Instead of closing the window when pressing the back button, perhaps call Qt.openUrlExternally(application:///ubuntu-system-settings.desktop) first to switch back to the system-settings app. This should promote the system-settings if it's already running (which it will be).

In the system-settings app, you can also use Qt.openUrlExternally(application:///online-accounts-ui.desktop) to launch online-accounts and this will also promote it if it's already running.

[Michał Sawicz (saviq)]

This is because the signon ui is dbus-triggered, and waiting for 5s after its last window closes. unity-mir currently doesn't consider surfaces to see whether an app is still there, instead it considers the session, even if there are no surfaces for that session.

I think there was a bug on this already, but can't find it...

[Selene ToyKeeper (toykeeper)]

Utopic 161 still does this, though the symptoms are different and it usually only shows the black screen for about a second.

Once in a while though, it'll show for more like 20 seconds, complete with the blank entry in the app switcher, and often a crash afterward. Not a unity8 crash though, just the app.

Also related is Bug #1269841, which prevents the user from running the accounts app twice in the same boot.

[David Barth (dbarth)]

This should be gone as of r199 and later. The Accounts settings is now a regular plugin of Ubuntu System Settings, ie it does not call an external process anymore. Besides it now uses the Trusted Session prompts to manage the creation of accounts.