Lacking an XKB component ...

From xkbdesc, the following changes:
rules/xfree86:
  + Remove ca, hu, mn and vn layouts from $oldlayouts.
  + Remove special case that causes PC keyboard models with the us_intl
    layout to load the us layout and add the us_intl layout to it.

symbols/group:
  + Add "rctrl_switch" needed by the ca layout.

symbols/keypad:
  + Add "comma" needed by the hu layout.

symbols/pc/Imakefile:
  + Add ca, ch, hu, jp, mn and vn.

symbols/pc/us:
  + Add two new variants: 'intl' and 'alt-intl'.  The latter is a strict
    replacement for us_intl, which will become obsolete soon.  Providing
    all alternatives will help users to migrate to the new files.


... and from Debian:
Fix the latin(type3) PC keyboard map to override the AB10 key definition
inherited from the basic layout, mapping the key to "minus, underscore"
rather than "slash, question".  This enables the al (Albanian), hr
(Croatian), pl2 (Polish QWERTZ), si (Slovenian), and yu (Yugoslavian)
layouts to inherit this key mapping (though al overrides it).  See Debian
#236604.

German keyboards using the "nodeadkeys" variant should produce an
apostrophe, not an acute accent, when <AE12> is pressed.  This change is
also consistent with the existing xc/programs/xkbcomp/symbols/de file.
See Debian bug #241127.

Provide XKB configuration option for Scroll Lock to be used as a group
toggle key.

Fix problem with numbers and symbols being un-typable in the Lithuanian keymap.
Fix a few problems with the U.K. Macintosh keyboard layout:
  * Map <TLDE> key to "section, plusminus".
  * Map <LSGT> key to "quoteleft, asciitilde".
  * Map AltGr+<AE02> to "EuroSign".
  * Include group(switch) symbols so that the already-defined mapping
    of AltGr+<AE03) to "numbersign" can be used.

Also see Debian #201737.

Implement option to place Compose key ("Multi_key") on <CAPS> key.  See
Debian #251310.

(and a patch to fix the separator on Polish keyboards)

Fix inconsistencies in rules/xfree86* files.

rules/xfree86:
  + List in $oldlayouts all layouts which are currently not multi-layout
    aware in the Debian xlibs package, including hu_US (thanks, Veres
    Lajos).  (Closes: #247463, #270810)
  + Support the lv3:ralt_switch option, which exists in xfree86.lst but was
    forgotten in this file.
  + Add support for a lv3:ralt_switch_multikey option.
  + Move lv3 definitions after altwin so that the former can override
    the latter.  See Bug#276143.

rules/xfree86.{lst,xml}:
  + Replace the options altwin:meta_super and altwin:meta_hyper with the
    correct names altwin:super_win and altwin:hyper_win.  (Closes: #271259)
  + Synchronize these files.

Replace level3(ralt_switch_multikey) by level3(ralt_switch) in all
layouts so that symbols on the 4th column may be accessed with
Shift+Alt_R or Alt_R+Shift.  (Closes: #270235)

Add support for standard Ctrl+Alt sequences to Sun keyboards.

Add support for RiscPC keycodes.  See Debian #141392.


... phew!  All the Debian bugs (#nnnnnn) can be accessed by going to
http://bugs.debian.org/nnnnnn.  Almost of them are written by Denis Barbier, who
knows more about XKB than I can hope to ever forget.  For best results, apply
all these patches in sequence (from first patch number through last).  Stir
sharply, do not shake.