I'm afraid I'm not sure of the appropriate component; my apologies. This request stems from http://bugzilla.gnome.org/show_bug.cgi?id=125492. If a focus window becomes not viewable, then X states that the new focus window depends on the revertto argument. If revertto is Parent, the focus reverts to the parent (or the closest viewable ancestor) and the new revertto value is taken to be None. However, if the Parent also becomes unviewable, then the focus reverts to nothing which means that window manager keybindings break. For now, we've added a hack to detect when no window becomes focused and manually focus a window (our dummy "no_focus_window") so that keybindings don't stop working. As Havoc says in comment 9 (http://bugzilla.gnome.org/show_bug.cgi?id=125492#c9) of the gnome bug, "An X extension to let us specify "revert to some specified window" (with side effect that RevertToNone will never be used) would be welcome"
The impact of this bug is small with the hack in metacity to always immediately set the focus if it gets set to None somehow, but without that window manager hack the impact is large since keyboard-only users (disabled users, etc.) can lose all ability to control the computer. I've been trying to think of how an app could depend on RevertToNone existing/working (since such an app would break in the presence of either the metacity hack or changing X to never use RevertToNone) but I can't really think of a scenario. Does anyone remember why RevertToNone exists in the first place?
Flagging as an enhancement.
Sorry about the phenomenal bug spam, guys. Adding xorg-team@ to the QA contact so bugs don't get lost in future.
This bug has been sitting untouched for a long time. If this is still a problem, please reopen, but I suspect it won't get much love. Patches welcome... =/
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