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Back to the future: backspace broken

Posted:
May 30th, '12, 11:12
by ihowarth
After upgrading from Mageia 1 to Mageia 2, backspace doesn't work in konsole. I haven't seen this sort of problem for at least 10 years! Anyone got any ideas?
Details:
I'm running konsole with tcsh and "linux console" keybindings - backspace mapped to \x7f (matches other machines where there's no problem).
Backspace works fine in emacs (and the same keyboard is used on other machines through a KVM switch), so it's not a hardware issue
"stty -a" shows "erase = ^?" (matches other machines where there's no problem)
Control-H works (but who wants to use two keys when one should do?!)
Re: Back to the future: backspace broken

Posted:
May 30th, '12, 19:57
by doktor5000
What events are registered when you start xev and then press backspace?
Re: Back to the future: backspace broken

Posted:
Jun 1st, '12, 12:28
by ihowarth
Thanks for the tip (never come across xev before); In "broken" konsole:
- Code: Select all
KeyPress event, serial 40, synthetic NO, window 0x3c00001,
root 0x10b, subw 0x0, time 2120685, (495,811), root:(498,835),
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 40, synthetic NO, window 0x3c00001,
root 0x10b, subw 0x0, time 2120738, (495,811), root:(498,835),
state 0x10, keycode 22 (keysym 0xff08, BackSpace), same_screen YES,
XLookupString gives 1 bytes: (08) "
XFilterEvent returns: False
On a "working" machine:
- Code: Select all
KeyPress event, serial 38, synthetic NO, window 0x3800001,
root 0x1ad, subw 0x0, time 8640488, (-312,465), root:(651,489),
state 0x0, keycode 22 (keysym 0xff08, BackSpace), same_screen YES,
XLookupString gives 1 bytes: (08) "
XmbLookupString gives 1 bytes: (08) "
XFilterEvent returns: False
KeyRelease event, serial 41, synthetic NO, window 0x3800001,
root 0x1ad, subw 0x0, time 8640562, (-312,465), root:(651,489),
state 0x0, keycode 22 (keysym 0xff08, BackSpace), same_screen YES,
XLookupString gives 1 bytes: (08) "
XFilterEvent returns: False
Don't know if this tells you anything....looks functionally identical on both machines to me.
More diagnostic info(?): running xterm (or aterm) from within a "broken" konsole, then backspace doesn't work in the new windows. (It does work when these terminals are fired up on a backspace-working machine).
However, if i ssh from the "broken" machine into a "working" machine, backspace works there...
Re: Back to the future: backspace broken

Posted:
Jun 1st, '12, 13:08
by isadora
Re: Back to the future: backspace broken

Posted:
Jun 1st, '12, 15:50
by ihowarth
Updates:
.../konsole/linux.keytab is identical in the "working" and "broken" machines, as is .Xdefaults
Editing keytab from within konsole ("settings"=>"configure current profile"=>"input"=>edit linux console) - changing backspace from \x7f to \b restores correct behaviour in local konsole, but then backspace (and ^H) are disabled when i ssh out to other machines
And just realised that backspace in konsole is acting as delete (i.e., is deleting the character under the cursor without moving the cursor; not deleting the character before the cursor). (And when backspace is locally \b, it acts as "delete" on remote machines)
Backspace seems to be okay in all other apps (e.g., the browser i'm using to type this in...)
Re: Back to the future: backspace broken

Posted:
Jun 2nd, '12, 19:20
by doktor5000
Sorry, this is a bit over my head, i'm afraid. Can't help you with this one (actually it's more a lack of time and masses of support replies to write around here, or i'd take a look as i'm curious about such problems, as there's usuallly much to learn from something like that). If it persists, file a bug:
https://wiki.mageia.org/en/How_to_report_a_bug_properly
Re: Back to the future: backspace broken

Posted:
Jun 9th, '12, 22:17
by ihowarth
No worries, i'll keep tinkering...it'll surely be something "obvious" (and, no doubt, user error rather than a bug)
Re: Back to the future: backspace broken

Posted:
Jun 10th, '12, 22:55
by ihowarth
I accidentally "reinstalled" Mageia-2 from DVD on a machine that had already been upgraded online from Mageia-1. (How/why? I needed to reboot from DVD, and if you're not paying attention the DVD defaults to install...and there's no "quit" option once started..) This doesn't seem to have done much damage (just lost repositories), except that backspace started behaving like del on this machine, too. So: upgrading on-line, no problem; upgrading from DVD, backspace breaks.
Anyway, solution now found: exhaustive comparison of configurations between machines with & without working backspace eventually showed the following differences through "bindkey":
"^H" -> backward-delete-char
"^?" -> delete-char
on broken machine, and
"^H" -> delete-char
"^?" -> backward-delete-char
on working machine. Solution is therefore to put
bindkey "^H" delete-char
bindkey "^?" backward-delete-char
into .tcshrc
[Anyone know where the default bindkey settings are configured?]