bug#729: 23.0.60; RET doesn't DTRT in read-char-exclusive on the Mac OS X --with-ns port

[Teodor Zlatanov <tzz@lifelogs.com>]

I found the problem while trying to use `read-passwd', which calls
`read-char-exclusive'.  Hitting RET is not registered correctly by
`read-char-exclusive' as it's called from `read-passwd' (it seems to
extend the input field downwards as if it was a multiline input field)
and so `read-passwd' doesn't terminate.  A workaround is to press C-m
in the input field.  This breaks EPA functionality when passphrases
are needed, and probably more packages as well.

Test with:



In GNU Emacs 23.0.60.8 (i386-apple-darwin9.4.0, *Step 9.0)
 of 2008-08-16 on mungo
Windowing system distributor `Apple', version 49.46.48
configured using `configure  '--with-ns' 'CC=gcc''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: nil
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Group

Minor modes in effect:
  gnus-topic-mode: t
  gnus-undo-mode: t
  recentf-mode: t
  auto-image-file-mode: t
  cua-mode: t
  display-time-mode: t
  icomplete-mode: t
  show-paren-mode: t
  which-function-mode: t
  url-handler-mode: t
  auto-insert-mode: t
  shell-dirtrack-mode: t
  df-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t