Comment 2 for bug 1314236

@Mateusz I can't tell whether you're agreeing or not. Your second sentence ("If for example...") is not generally true for me. I am quite confident that 14.04 is subtly different from 13.10 in the timing and sequencing criteria for Alt and Alt-key discrimination.

The best demonstration of this is to consciously hold Alt then hit D (or any other key). If I do this slowly, HUD does not appear (that is, works as expected). If I do this quickly while being careful to maintain Alt-then-key ordering, HUD appears as described. The same behavior occurs for B (backward-word) and F (forward-word), etc.

In fact, HUD appears only with short Alt keydown-up events; it does not appear with long Alt keypresses. This is irrespective of another key event.

So, in my case, a fast Alt-anything brings up HUD whereas a slow Alt-anything doesn't because Alt his held briefly in the first case and longer in the second.