Emacs Bug: universal argument & key-translation-map disables undo.

[Xah Lee]

Emacs Bug: universal argument & key-translation-map disables undo.

This seems like a bug. Steps to reproduce:

• Start GNU Emacs 23.2 with “-Q”. (so it doesn't load any custome init
files.)

• Evaluate this: (define-key key-translation-map (kbd "M--") (kbd
"─")) (it lets you press 【Alt+-】 to insert a unicode char “BOX
DRAWINGS LIGHT HORIZONTAL” (U+2500).)

• Open a new buffer.

• Type 【C-u 30 M--】. (insert the char 30 times.)

• You get this error: universal-argument-other-key: Args out of range:
" ─", 0, 7

• Now, do Type 【C-u 30 M--】 again. This time, no problem.

• The worst problem is this: Now, when you try to undo, emacs says “No
further undo information”.

Notes: The exactly unicode char doesn't matter. The key used doesn't
seem to matter neither. Perhaps even unicode doesn't matter. The
problem seems to be using “key-translation-map” and with universal
argument.

 Xah