AltGr sometimes generates Control_L

[Hannu Koivisto <azure at iki dot fi>]

Greetings,

I run Cygwin/X with "XWin.exe -multiwindow -clipboard
-silent-dup-error".  I start xev from shell and start
pressing(&releasing) "a" and "AltGr" keys consecutively: a AltGr a
AltGr ...

If I'm lucky, pressing and releasing "a" results to...

---8<----------------------------------------------------------
KeyPress event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1906663234, (595,1269), root:(771,1501),
    state 0x10, keycode 38 (keysym 0x61, a), same_screen YES,
    XLookupString gives 1 bytes: (61) "a"
    XmbLookupString gives 1 bytes: (61) "a"
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1906663312, (595,1269), root:(771,1501),
    state 0x10, keycode 38 (keysym 0x61, a), same_screen YES,
    XLookupString gives 1 bytes: (61) "a"
    XFilterEvent returns: False
---8<----------------------------------------------------------

...and pressing and releasing AltGr results to...

---8<----------------------------------------------------------
KeyPress event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1906710515, (595,1269), root:(771,1501),
    state 0x10, keycode 113 (keysym 0xfe03, ISO_Level3_Shift), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1906710609, (595,1269), root:(771,1501),
    state 0x90, keycode 113 (keysym 0xfe03, ISO_Level3_Shift), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False
---8<----------------------------------------------------------

Unfortunately, sometimes pressing and releasing "a" resulted to...

---8<----------------------------------------------------------
KeyPress event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1906670500, (595,1269), root:(771,1501),
    state 0x14, keycode 38 (keysym 0x61, a), same_screen YES,
    XLookupString gives 1 bytes: (01) "â"
    XmbLookupString gives 1 bytes: (01) "â"
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1906670593, (595,1269), root:(771,1501),
    state 0x14, keycode 38 (keysym 0x61, a), same_screen YES,
    XLookupString gives 1 bytes: (01) "â"
    XFilterEvent returns: False
---8<----------------------------------------------------------

...where the string looked like a happy face.

But a bigger problem is that AltGr sometimes generates Control_L
in addition to ISO_Level3_Shift, which makes Emacs (which I run
from a Linux machine remotely over X) quite unhappy.  For example,
when I'm trying to enter "}", which in Finnish layout is done by
AltGr+0, Emacs complains that C-} is undefined.

---8<----------------------------------------------------------
KeyPress event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1907120437, (478,827), root:(676,1088),
    state 0x10, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyPress event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1907120437, (478,827), root:(676,1088),
    state 0x14, keycode 113 (keysym 0xfe03, ISO_Level3_Shift), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1907120531, (478,827), root:(676,1088),
    state 0x94, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1907120531, (478,827), root:(676,1088),
    state 0x90, keycode 113 (keysym 0xfe03, ISO_Level3_Shift), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

EnterNotify event, serial 27, synthetic NO, window 0xe00001,
    root 0x7c, subw 0x0, time 1907125468, (167,87), root:(365,348),
    mode NotifyNormal, detail NotifyNonlinear, same_screen YES,
    focus YES, state 16
---8<----------------------------------------------------------

I've seen earlier complaints about the same problem dating back to
2005 but nothing that would help me solve this problem.

I'm using cygwin in Windows XP SP3.  Package versions:

cygwin                          1.5.25-15
libX11_6                        1.1.5-2
xorg-server                     1.5.3-7
xorg-x11-base                   7.4-1
xorg-x11-bin                    7.4-1
xorg-x11-bin-dlls               7.4-1
xorg-x11-bin-lndir              7.4-1
xorg-x11-etc                    7.4-1
xorg-x11-fenc                   7.4-1
xorg-x11-fnts                   7.4-1
xorg-x11-libs-data              7.4-1
xorg-x11-xwin                   7.4-1

-- 
Hannu


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://x.cygwin.com/docs/
FAQ:                   http://x.cygwin.com/docs/faq/