Comment 2 for bug 1515881

FWIW, I tried qterminal (https://github.com/qterminal), whose code was originally based on konsole. As in konsole, the qt4 version works OK but the qt5 version does not send CTRL+Space so either qterminal and konsole both do the same thing wrong or this is broken at a deeper level in qt5. Notice that you can't send CTRL+@ either, so this looks like something deeper than keyboard bindings, i.e., it looks like konsole/qterminal cannot send ASCII char 0.