[SOLVED] Shift+Backspace Does Nothing

tacostick · 2011-10-21 23:50:55

This is a weird issue. In Xorg, pressing 'backspace' while holding 'shift' does not result in a backspace, although holding shift and pressing any other key works as intended.

It works fine in virtual consoles.

I have tried resetting the keymap:

$ setxkbmap us

...to no avail. I'm not really sure what the best way to go about fixing this would be, but as you can imagine, it's annoying when I'm typing something in capitals and want to hit backspace (happens surprisingly frequently).

Any help is appreciated.

Last edited by tacostick (2011-10-25 17:22:48)

Mike Rofone · 2011-10-25 14:27:23

Good to see that I am not the only one experiencing this problem.

The behaviour of Shift+Backspace must have changed in the last one or two weeks, as I only experience the problem since updating two days ago, and the next oldest update was approx. one to two weeks old. Sorry for not providing any version numbers, but I would not know which packages are likely to be relevant for the issue. I will happily supply any information needed, e.g. current and previous package versions of relevant packages (I guess it can be reconstructed from the pacman cache, right?).

Like tacostick said, Shift-Backspacing is also a regular occurrence while coding for me and quite annoying, so any ideas are welcome

tacostick · 2011-10-25 16:44:37

Yeah, I couldn't possibly name a package at fault. Xorg? It's too easy to blame shit on Xorg.

Please, do let me know if you figure this one out.

Mike Rofone · 2011-10-25 16:59:41

I just checked the keystrokes being generated using xev. The results look strange.

xev for Backspace push:

KeyPress event, serial 33, synthetic NO, window 0x4c00001,
    root 0x15d, subw 0x0, time 29980681, (73,97), root:(81,175),
    state 0x10, keycode 22 (keysym 0xff08, BackSpace), same_screen YES,
    XLookupString gives 1 bytes: (08) "
    XmbLookupString gives 1 bytes: (08) "
    XFilterEvent returns: False

KeyRelease event, serial 33, synthetic NO, window 0x4c00001,
    root 0x15d, subw 0x0, time 29980761, (73,97), root:(81,175),
    state 0x10, keycode 22 (keysym 0xff08, BackSpace), same_screen YES,
    XLookupString gives 1 bytes: (08) "
    XFilterEvent returns: False

xev for Shift+Backspace:

KeyPress event, serial 33, synthetic NO, window 0x4c00001,
    root 0x15d, subw 0x0, time 29982505, (73,97), root:(81,175),
    state 0x10, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyPress event, serial 33, synthetic NO, window 0x4c00001,
    root 0x15d, subw 0x0, time 29982905, (73,97), root:(81,175),
    state 0x11, keycode 22 (keysym 0xffffff, VoidSymbol), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 33, synthetic NO, window 0x4c00001,
    root 0x15d, subw 0x0, time 29982969, (73,97), root:(81,175),
    state 0x11, keycode 22 (keysym 0xffffff, VoidSymbol), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 33, synthetic NO, window 0x4c00001,
    root 0x15d, subw 0x0, time 29983145, (73,97), root:(81,175),
    state 0x11, keycode 50 (keysym 0xffe5, Caps_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

I guess the problem is that Backspace with Shift produces a "VoidSymbol" with keysym 0xffffff which looks like some strange placeholder. But I don't know where to look next...

EDIT:
Seems like a side-effect of this bugfix: https://bugs.freedesktop.org/show_bug.cgi?id=41297
The problem of Shift+Backspace killing X unexpectedly was solved by erasing the bindings for Backspace with any modifier keys (see Comment #4 in the bug).

From the reports at http://www.spinics.net/lists/xorg/msg53099.html (which I guess lead to the bugfix in the beginning) I also found how to fix it:

xmodmap -e "keycode 22 = BackSpace BackSpace BackSpace VoidSymbol VoidSymbol VoidSymbol Terminate_Server"

and Shift+Backspace works as desired again. The difference in this line to the one proposed in the aforementioned report is that the second action "VoidSymbol" has been replaced by "BackSpace".

For a permanent fix (though I did not try re-logging) it seems one can alter /usr/share/X11/xkb/symbols/terminate accordingly.
I guess this should be reported as a follow-up bug, which I can do later this evening.

Last edited by Mike Rofone (2011-10-25 17:16:33)

tacostick · 2011-10-25 17:22:20

This is everything I love about Linux.

Thanks so much! SOLVED.

piojo · 2011-11-16 07:00:30

I found that I also need to use Shift+F3 a lot, so I ran:
xmodmap -e 'keycode 69 = F3 F3 VoidSymbol VoidSymbol VoidSymbol XF86Switch_VT_3 VoidSymbol VoidSymbol XF86Switch_VT_3'
(This was based on the output of "xmodmap -pke | grep F3", so adjust it accordingly.)

Is there some place we should report this as an upstream bug?

Last edited by piojo (2011-11-16 07:00:50)

Vain · 2011-11-16 08:56:42

Hi,

I think this has already been fixed upstream:

http://cgit.freedesktop.org/xkeyboard-c … 43a4d87f0d

But there hasn’t been a new release since 2.4.1.

Arch Linux

#1 2011-10-21 23:50:55

[SOLVED] Shift+Backspace Does Nothing

#2 2011-10-25 14:27:23

Re: [SOLVED] Shift+Backspace Does Nothing

#3 2011-10-25 16:44:37

Re: [SOLVED] Shift+Backspace Does Nothing

#4 2011-10-25 16:59:41

Re: [SOLVED] Shift+Backspace Does Nothing

#5 2011-10-25 17:22:20

Re: [SOLVED] Shift+Backspace Does Nothing

#6 2011-11-16 07:00:30

Re: [SOLVED] Shift+Backspace Does Nothing

#7 2011-11-16 08:56:42

Re: [SOLVED] Shift+Backspace Does Nothing

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