Xmir -rootless: Menus/dialogs sometimes appear in the wrong place

[Daniel van Vugt]

Xmir: Menus/dialogs sometimes appear in the wrong place when using -rootless

In the past fortnight I've got menu placement working for the first time. However if you use an app for a little while its sub-surface placement (including menus) will sometimes get confused. And menus start to appear more around the middle of the app window.

[Daniel van Vugt (vanvugt)]

At least in the case of -rootless -flatten, part of the problem appears to be double-reparenting. Apps like GIMP seem to keep their menu windows around even when they're not visible, presumably to help with menu scrolling performance. However Xmir has to re-realize and hence tries to re-reparent the menu windows each time. And it appears on the second and subsequent opening, a menu's relative position shifts in an unwanted way.

Without figuring out the root cause we could just avoid redundant reparenting, however that seems to create a worse problem whereby the menu goes invisible. Because we seem to need the extra reparenting to kick the XComposite logic into action. So more investigation required...

[Daniel van Vugt (vanvugt)]

Dropped severity as I can only reproduce this in -flatten mode now (which nobody should really use)