bug#17331: 24.4.50; `display' text property with mouse movement - tooltip not updated

[Eli Zaretskii]

> Date: Wed, 23 Apr 2014 15:10:54 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> Put these lines in a buffer.
> 
> ;; AAAAAAAAAAAAAAAAAAAAA
> ;; BBBBBBBBBBBBBBBBBBBBB
> 
> Use these sexps to add a `help-echo' property, with point on the first
> line for the first sexp and point on the second line for the second
> sexp.
> 
> (add-text-properties
>  (line-beginning-position) (line-end-position)
>  '(mouse-face highlight help-echo "1111111111111111"))
> 
> (add-text-properties
>  (line-beginning-position) (line-end-position)
>  '(mouse-face highlight help-echo "2222222222222222"))
> 
> Now move the mouse over the first line, then the second line, without
> moving it outside the line text (i.e., keep it within the mouse-face
> area).
> 
> When you move the mouse between the lines, the tooltip text changes, as
> it should.
> 
> Now do the same thing, but using these sexps:
> 
> (add-text-properties
>  (line-beginning-position) (line-end-position)
>  '(mouse-face highlight help-echo
>    (propertize " " 'display "1111111111111111")))
> 
> (add-text-properties
>  (line-beginning-position) (line-end-position)
>  '(mouse-face highlight help-echo
>    (propertize " " 'display "2222222222222222")))
> 
> The tooltip does not change as it should.  To get it to change, you need
> to move the mouse outside of the current line's propertized text before
> moving it over the other line's text.

Fixed for Emacs 24.4 (emacs-24 branch revision 117017).