This bug was-reenter from the old bug posted at http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=97460. Last time, it can be resolved by uncomment "nonlatin" in the rules file. That does not works for /usr/X11/lib/X11/xkb/rules/xorg. Although the us keymap is implicitly included in keyboard layout chain, I still can not press Ctrl-c while in non-latin keyboard layout (such as th).
Created attachment 1313 [details] This file is generated from "xkbcomp :0.0 -xkb"
i don't think this is inconsistent with the spec at all. xkb specifies only a Ctrl+(letter) translation to control codes, and nothing else. in the current group, Ctrl+(thai symbol), is just that: the Thai symbol with ctrl as a modifier. whatever implements the key bindings should be cycling through all the groups to determine if there's an applicable binding.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.