Comment 45 for bug 923410

On Tue, May 15, 2012 at 04:15:31PM -0000, Gerry Boland wrote:
> The tap detection code does indeed take into account all other
> keypresses. The HUD should only show if you press & release the Alt key
> quickly, and having pressed no other key in the mean time. Perhaps some
> keys are not reported correctly. xev output would help us.

Here's some xev output. But doesn't this suffer from the fundamental
problem that xev only shows the keypresses that are seen by the xev window?
(Whereas Alt+Tab is handled by the WM)

> Any steps to reproduce and information about your system would be useful.
> External/internal keyboard, computer model, etc.

External keyboard, ThinkPad X201, user who is very fast at Alt+Tab'ing ;)

FocusIn event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyWhileGrabbed, detail NotifyNonlinear

KeymapNotify event, serial 33, synthetic NO, window 0x0,
    keys: 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

FocusIn event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 33, synthetic NO, window 0x0,
    keys: 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

KeyPress event, serial 33, synthetic NO, window 0x4c00001,
    root 0xbf, subw 0x0, time 922669940, (891,788), root:(893,868),
    state 0x0, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

FocusOut event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyGrab, detail NotifyAncestor

FocusOut event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyWhileGrabbed, detail NotifyNonlinear

FocusIn event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyWhileGrabbed, detail NotifyNonlinear

KeymapNotify event, serial 33, synthetic NO, window 0x0,
    keys: 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

FocusIn event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 33, synthetic NO, window 0x0,
    keys: 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

FocusOut event, serial 33, synthetic NO, window 0x4c00001,
    mode NotifyNormal, detail NotifyNonlinear