Ubuntu – Delayed touchpad scroll event causes crazy zooming if top of the page is reached

I have been experiencing this issue for years and that is quite annoying 🙂

If I scroll down using "two finger" touchpad gesture, the scroll itself takes effect immediately. But if I'm on the top of the page and I (occasionally) scroll up and then (within 2-3 secs after finishing scrolling and releasing the touchpad) press Ctrl, system interprets these two events (scroll and ctrl) as a single Scroll+Ctrl event as and starts zooming everything crazy, even though these events are not overlapping (and even have 2-3 seconds between them).

Typical scenario: I'm scrolling a page, hit the top of the page, wait a little (1-3 sec), then press Ctr-Tab and together with switching the tab, I also get both of my tabs content zoomed crazily (typically ~700% in chrome). And that's somewhat annoying, because you have to 1) wait until chrome re-renders it with a new scale 2) press Ctrl-0 3) wait until in re-renders it again with a default scale 🙂

An interesting detail is that I do not observe this behavior in any application if scroll event was successfully "dispatched as a scroll": if I'm not hitting the top of the page yet, and scroll up, and press Ctrl immediately – no zooming takes place (as if – as soon as it is not the top of the page – this "scroll" was successfully "eaten"="dispatched" by the target app and removed from event queue).

System and UI themselves run super-smoothly so it's definitely not an event-handling lag.

This guy describes similar experiance here: Mouse wheel scroll events persist after hitting meta key

Or there might be a tweak for Unity that disables zooming scroll behavior at all? (like this: How to disable ctrl + scroll zoom in Lubuntu or openbox )

Ubuntu 14.04.4

Acer Aspire V5-171

Graphics: Intel HD 4000 (out-of-box drivers)