xkb changes state on Shift/Alt press even when modmap is empty
Submitted by Adam Tkac
Assigned to Xorg Project Team
Description
I completely cleared Xorg modifier map (modmap):
$ ./clearmods
- xmodmap -e 'clear shift'
- xmodmap -e 'clear lock'
- xmodmap -e 'clear control'
- xmodmap -e 'clear mod1'
- xmodmap -e 'clear mod2'
- xmodmap -e 'clear mod3'
- xmodmap -e 'clear mod4'
- xmodmap -e 'clear mod5'
$ xmodmap xmodmap: up to 0 keys per modifier, (keycodes in parentheses):
shift
lock
control
mod1
mod2
mod3
mod4
mod5
As you can see there is no keysym mapped as modifier. Now I press the "Shift_L" key, for example, and get following in xev:
KeyPress event, serial 23, synthetic NO, window 0x200001, root 0x12c, subw 0x0, time 12108291, (109,83), root:(111,85), state 0x0, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES, XLookupString gives 0 bytes: XmbLookupString gives 0 bytes: XFilterEvent returns: False
KeyRelease event, serial 26, synthetic NO, window 0x200001, root 0x12c, subw 0x0, time 12108419, (109,83), root:(111,85), state 0x1, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES, XLookupString gives 0 bytes: XFilterEvent returns: False
You can see that state is changed from 0x0 to 0x1 which means server thinks the shift was pressed but it shouldn't because it is not mapped to "shift" modifier in modmap. This also happens for "Alt" key which is usually mapped to "mod1" modifier.
However when I unmap all keysyms associated with "control" modifier server recognizes it correctly and no longer changes state from 0x0 to 0x4 when I press CTRL.
Reproducible with the latest Xorg (I have 1.9.99.1). Let me know if you need more info.
Version: git