Because of bug 806029, we never drop window buffers (youch). We're supposed to have been all along. That's allowed a few bugs to creep into the window manager. Case 1 (1) Go to homescreen (2) Open app A (3) Press HOME button At the beginning of the animation, A is hidden and the homescreen is shown. This leads to A flashing white with the patches in bug 806029. Instead, A shouldn't be hidden until the animation completes. Case 2 (1) Go to homescreen (2) Open app A (3) Press HOME button (4) Tap A's icon to open it again A isn't made visible until the end of the opening animation. This makes it appear blank white the entire time. Instead, A should be made visible at the beginning of the animation. Case 3 (1) Go to homescreen (2) Open the dialer (3) Go back to homescreen (4) Open contacts app (5) [Open task switcher to make sure both are still running] (6) Choose a contact in the contacts app and tap to make a phone call The contacts app is hidden at the beginning of the animation so it appears white until we switch to its screenshot. The dialer isn't made visible until the *end* of the animation, so it appears white when we're not showing its screenshot. (I confirmed the hidden/visible states by instrumenting the code that eventually runs when mozbrowser.setVisible(true/false) is called. The flashes of white aren't a gecko bug.)

Not a functional dependency, but bug 803447 is a pretty big refactoring that I don't want this code to rot.

Tim, this is the part 1 work we discussed.

Bug 806029 is already landed, we will need this patch to properly show apps during transitions. [Approval Request Comment] Bug caused by (feature/regressing bug #): Bug 806029 User impact if declined: Use will see blank apps during opening/closing transition Testing completed: yes, on Otoro Risk to taking this patch (and alternatives if risky): this patch only touches window manager.

Comment on attachment 679851 [details] Github: https://github.com/mozilla-b2g/gaia/pull/6299 Followup of a blocker. I believe this is a blocker too that does not need any approval.

Comment on attachment 679851 [details] Github: https://github.com/mozilla-b2g/gaia/pull/6299 https://github.com/mozilla-b2g/gaia/commit/2de951b2376705dd903604909fda2599212221c2

I don't understand why this doesn't fit in the system component. I thought it did?