bug#12067: 24.1; improper menu formatting with multiple \t chars

[Eli Zaretskii <eliz@gnu.org>]

> From: "Drew Adams" <drew.adams@oracle.com>
> Date: Thu, 26 Jul 2012 23:49:55 -0700
> 
> emacs -Q
> 
> (defcustom foo [:ascii:]
>   "..."
>   :type
>   '(choice :tag "Foobar"
>     (const :tag "A\t\t- [:ascii:]"                                [:ascii:])
>     (const :tag "Bbbbbb\t\t- [:nonascii:]"                        [:nonascii:])
>     (const :tag "Cccccccccccc\t\t- [:word:]"                      [:word:])
>     (const :tag "Dddddddddddddddddddddddddd\t\t- [:alnum:]"       [:alnum:])
>     (const :tag "Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\t- [:alpha:]" [:alpha:]))
>   :group 'convenience)
> 
> M-x customize-option foo
>  
> Click button Value Menu to see the menu.  Each time \t\t is used, there
> is a rectangular artifact added also.

I cannot reproduce this here, neither in Emacs 24.1 nor in the current
trunk version.

What I did was copy-paste your example to a fresh Emacs session, then
"M-x eval-region RET", then "M-x customize-option RET foo RET" and
click the "Value Menu" to display the menu.  It displayed correctly,
nicely aligned and with no artifacts.