bug#12615: 24.2.50; Non-ignored case in insert-char

[Harald Hanche-Olsen <hanche@math.ntnu.no>]

Starting with emacs -Q:

Evaluate the following in the *scratch* buffer:
(make-local-variable 'completion-ignore-case)
Then type: C-x 8 C-m a TAB

Expected result:
  A completion list of unicode names starting with the letter A.
Actual result:
  [no match]

Some observations: C-x 8 C-m is bound to insert-char, a C function.
And insert-char calls read-char-by-name, which let-binds
completion-ignore-case to t. The clear intention is that unicode name
searches should always be case insensitive, and this seems always to
be the case if completion-ignore-case is not buffer local.

Setting completion-ignore-case to t in the *scratch* buffer still does
not help.

In GNU Emacs 24.2.50.1 (x86_64-apple-darwin11.4.0, NS apple-appkit-1138.47)
 of 2012-09-24 on airy
Bzr revision: 110175 rgm@gnu.org-20120924063102-7nllu1xpqi4f24n7
Windowing system distributor `Apple', version 10.3.1138
Configured using:
 `configure '--with-ns''

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

I have also seen this on a quite recent emacs on x86_64-unknown-linux-gnu.

- Harald