linuxmint/Cinnamon — pull request #933 by autarkper (2012-07-19 09:24:57+00:00)
Title: "Log level 16: invalid (NULL) pointer instance" exiting Expo

Using Main.getTabList in Expo causes strange warning messages when exiting Expo (except the first time):

Window manager warning: Log level 16: invalid (NULL) pointer instance

Window manager warning: Log level 8: g_signal_handlers_disconnect_matched: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed

Window manager warning: Log level 8: g_object_unref: assertion `G_IS_OBJECT (object)' failed

How to reproduce (current master):
1) Make sure you can see cinnamon's stdout and stderr output.
2) Open and close Expo twice. You will then see the warnings, one set for each workspace you have.

No other ill effects have been observed, but the warning messages are bad enough.
With the fix we lose the ability to show "orphan" dialogs in Expo.

As for the direct cause of the problem, I have no idea. Main.tabList works fine in all other places where it is used, and it seems not to be the call itself that is the problem but rather using the windows returned from it.