bug#3483: fill-column+1 problem

[Toru TSUNEYOSHI]

(I wrote the following...)
I think the problem is a bug obviously. (And I wish the bug fix.)
How do you (or maintainer) think about it?

From: Toru TSUNEYOSHI <t_tuneyosi@hotmail.com>
Subject: fill-column+1 problem
Date: Thu, 07 May 2009 20:00:08 +0900 (JST)
Message-ID: <20090507.200008.181206471.t_tuneyosi@hotmail.com>

> Hi. I met a problem about `fill-region-as-paragraph' on Emacs
> 22.3.1. (This problem happens on Emacs 23.0.93.1, because there is no
> change of the function's code.) Please read the following.
> 
> condition:
> 
>       fill-column => 10
> 
> === example 1 (no problems) ============================================
> 
> 12345678901234567890
> 
> あいうえおかきくけこ    <- fill-region (this function is a caller of
>                                       `fill-region-as-paragraph')
> 
> =>
> 
> あいうえお
> かきくけこ
> 
> ========================================================================
> 
> === example 2 (no good) ================================================
> 
> 123456789012345678901
> 
> あいxうえおかきくけこ   <- fill-region
> 
> =>
> 
> あいxうえお                <- fill-column+1 problem
> かきくけこ
> 
> ========================================================================

(I should have written "fill-column+alpha problem" not "fill-column+1
 problem". Because the problem is "fill-column+2 problem" if
 char-width (of char of end of line 1 after fill-region in example 2) is
 3.)