Keys are erroneously passed through to window on scratchpad (un)hide

[wilhelmy]

I show/hide the scratchpad with mod+space in my configuration.
When playing a youtube video, the video pauses on (mod+)space (other websites ignore modified space for pause), so whenever I hide the scratchpad, the video changes pause state.
IMO this shouldn't be passed through to the window.

[mbenkmann]

Let's be precise here. It's the key RELEASE that is being passed through. And it's only when the scratchpad is being hidden, because in this case the scratchpad window is destroyed faster than you can release the key, so the grab for the window disappears before the KeyRelease event is being dispatched.

This problem is a fundamental one that is unrelated to the scratchpad. It will pop up in any context where a keypress destroys the window that grabbed the key in question. When you dismiss a mod_menu.menu() by pressing ESC, the KeyRelease for ESC is also being passed on to the underlying window (I verified this using xev). The only reason you're noticing it with the scratchpad is the perfect combination of factors, i.e. the key binding for the scratchpad being SPACE and YouTube reacting to a key release of SPACE.

A simple workaround for this issue would be to change the default binding of scratchpad from kpress() to kpress_wait(). It's not a perfect solution because in theory you could release the modifier key before space. However the way most people press keys that's rarely going to happen.