bug#6933: 24.0.50; fringe-mode value of `half' is broken

[Chong Yidong <cyd@stupidchicken.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> This happens because fringe.el has this customization form for "half"
> in the defcustom for fringe-mode:
>
> 		 (const :tag "Half width" (5 . 5))
>
> And the doc string for fringe-mode says this, among the rest:
>
>                                This command may round up the left and
>     right width specifications to ensure that their sum is a multiple
>     of the character width of a frame.
>
> So 5 is rounded up to 8, and the rest is history.
>
> I don't know why the values are 5 instead of 4.  The default fringe
> width is 8 on all GUI displays, so half of that should have been 4,
> not 5.  Maybe I'm missing some subtlety here.
>
> Can someone please check on X whether (fringe-mode '(4 . 4)) does TRT?
> If it does, I think we should use 4 instead of 5 in the above
> defcustom.

(4 . 4) seems to work fine for me on X.