Ever since I moved my install from an old netbook to a new Braswell notebook I have been seeing occasions where Konsole stops responding to the keyboard.

This happens with Konsole4 but more often with Konsole5 (possibly because I use that version predominantly). I have not been able to determine what triggers the issue but it appears to have something to do with either rapid terminal output or else rapid keyboard input. The latest episode occurred when I was holding a cursor key down to scroll through the command history.

When the issue triggers, it affects either a single tab or else all tabs belonging to a given Konsole session. In the former case I can usually clone the affected tab and only use its shell history, in the latter case I have to restart Konsole entirely.

This is with Ubuntu 14.04.5 LTS with the "Xenial" enablement stack (= same Xorg as 16.04) and kernel 4.9.7 so all related drivers should be up-to-date.

I see I'm not the only one suffering from this (esp. #160329). Next time I'll try changing or restarting the window manager but I already have some more observations that may help pinpointing the cause:

- if the entire Konsole session is affected keyboard input is dysfunctional in dialogs too
- changing the keyboard layout doesn't help (neither in Konsole nor for the entire desktop)
- copy/paste continue to work (which has sometimes allowed me to exit vi gracefully)

The latter observation suggests an issue with state management in the keyboard event handling where Konsole inappropriately gets stuck in a mode where it discards all keystrokes (yes, that includes Ctrl-C, Ctrl-S Ctrl-Q etc.)