Setting keyboard shortcuts causes system to lock up

[Matthew Lemon]

When trying to change the keyboard shortcut for Start switcher (trying to assign Alt-Tab), system locks up and need to hard restart. Following that, can no longer change the shortcut via Ubuntu System Settings panel. System Settings allows assigning the new trigger but has no effect once set and shortcut triggered.

[J Phani Mahesh (phanimahesh)]

Can you please provide the following details?

1. Is this a persistent problem? If yes, can you provide a detailed sequence of steps to reproduce the issue? This will help in debugging and validating any fixes we make on our end.
2. What is the exact version you are running? If it is not the latest from the PPA, can you confirm that the bug exists in the latest daily build?
3. Which version of Ubuntu are you running?

[Seth Johnson (sethj)]

This is interesting. I can kind of reproduce this. If I change the shortcut to something non default (I used Alt+q) it works fine, but if I try to change it back to Alt+Tab it won't let me. While waiting for keyboard input the system does appear to 'freeze', but it's not a really frozen. If you press backspace to clear out the shortcut everything 'unfreezes'.

I guess there are two undesirable behaviours here:

- the tool should allow cancelling a shortcut change with the mouse (clicking on another shortcut should cancel the change)

- the tool should be able to accept tab as part of a shortcut.

It is interesting to note that the system settings application also experiences this 'freeze' while waiting for a keyboard combination. This could be a deeper bug.

Tested on 15.10 and UTT 0.0.7.