bug#15430: 24.3; ido-completing-read is not a replacement for completing-read

[Noam Postavsky]

Starting from emacs -Q -nw --eval "(setq completing-read-function
#'ido-completing-read)"

Then M-x gives
ido-set-matches: Wrong type argument: listp, [gnus-put-display-table
message-check-news-body-syntax gnus-make-overlay ido-save-history
message-check-element qp-or-base64 message-insert-wide-reply
help-xref-url-regexp ido-word-matching-substring gnus-set-file-modes
...]

I gather from http://thread.gmane.org/gmane.emacs.devel/134000 that
ido-completing-read is supposed to be wrapped, but there should at
least be some indication of this in the docstring. It certainly
shouldn't claim to be the "Ido replacement for the built-in
`completing-read'."


In GNU Emacs 24.3.1 (x86_64-unknown-linux-gnu, X toolkit)
 of 2013-08-23 on localhost
Configured using:
 `configure '-C' '--with-x-toolkit=lucid'
 '--without-toolkit-scroll-bars' '--with-gif=no' 'CFLAGS=-O2
 -march=native''