bug#14520: 24.3; minibuffer resizes when message contains bold or italic text

[Eli Zaretskii <eliz@gnu.org>]

> From: Klaus-Dieter Bauer <bauer.klaus.dieter@gmail.com>
> Date: Fri, 31 May 2013 16:28:53 +0200
> 
> When a message contains bold or italic text, the minibuffer is resized
> incorrectly.

Why do you think it is incorrect?

> (defun x () (interactive)
>   (let ((message "Hello World"))
>     (put-text-property 0 5 'face 'bold message)
>     (message message)))
> 
> (defun y () (interactive)
>   (let ((message "Hello World"))
>     (put-text-property 0 5 'face '(:foreground "blue") message)
>     (message message)))
> 
> On "M-x x" the minibuffer will look as if the message contained a
> trailing newline. On "M-x y" the minibuffer will display correctly.
> 
> eldoc's tips become distracting as this causes random flickering of the
> minibuffer while moving the cursor through code.
> 
> The problem is reproducible at least in all emacs-24.x-bin-i386.zip
> releases on http://ftp.gnu.org/gnu/emacs/windows/

It doesn't happen to me with 24.3, but that's on XP, while you are on
Windows 7.  So I'm quite sure it's a font and/or shaping engine thing.
Somehow, on your system the font tells Emacs that its height is more
than you think it should be.  Emacs has no alternative but to comply.