bug#2957: 23.0.92; ucs-insert: Completion does not work correctly with Unicode Character Name Input

[Andreas Schwab <schwab@linux-m68k.org>]

Ashutosh Mehra <ashutoshmehra@gmail.com> writes:

> BUG DESCRIPTION:
> When I type the following:
> C-x 8 RET greek letter alpha
> and press TAB, I get several choices for the greek letter alpha
> variants. But I'm unable to type anything into the minibuffer (neither
> SPC nor any character) -- Emacs just doesn't accept the input. If I
> press RET at this point, I get the error message "ucs-insert: Not a
> Unicode character code: nil".

This is a problem with partial-completion.  You can continue with C-q
SPC, or move back before "letter" and insert either "capital" or
"small".

Here is a reduced testcase:

(completing-read "Type a SPC b TAB: " '("a 1 b" "a 1 b c" "a 1 b d" "a 2 b" "a 2 b c" "a 2 b d"))

The minibuffer contents become "a SPC SPC b", indicating that a word is
missing between "a" and "b".  Either partial-completion should move
point back to where the word is missing or accept SPC as input.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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