bug#14306: Some line numbers missing when both whitespace and linum mode are enabled at the same time

[Eli Zaretskii]

> From: Artur Pacan <figaroap@gmail.com>
> Date: Mon, 29 Apr 2013 16:46:15 +0200
> 
> Easy to reproduce:
> 
> 1. Open any file with blank lines.
> 2. Enable linum-mode (line numbers displayed correctly)
> 3. Enable whitespace-mode (some line numbers, especially after a blank
> line are missing)
> 
> I've checked this on never emacs versions and it's not working
> correctly on any of them.

In fact, this bug was introduced 7 and a half years ago, and is
present in all versions since Emacs 22.1.  I guessed no one envisioned
a situation where there's an overlay with a before-string that has a
display property which specifies another string, and some of the
characters of that other string are displayed via display table...
(Are you dizzy yet?)

Now fixed in trunk revision 112465.

Thanks.