bug#27830: 26.0.50; Left fringe gets truncated by a pixel in window not sharing that edge with frame

[Kaushal Modi <kaushal.modi@gmail.com>]

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On Wed, Oct 4, 2017 at 5:04 AM martin rudalics <rudalics@gmx.at> wrote:

>
> I see that the continuation arrows in the rightmost fringe have their
> tips truncated.  Do you really need diff-hl-mode enabled to see that?
>

Can you try again with a buffer with wide enough lines to see the
> continuation arrows in the window on the right?  This is important
> because it would constitute another, probably different bug.
>

Hi Martin,

The screenshots attached in my previous email show the truncation arrows
with/without scrollbars.. they look the same in both cases to me (see
below, without scrollbars on left, and with, on right):

I am using diff-hl-mode because the truncation is very evident as you see
in that same image.

[image: image.png]


>  I see: The first pixel of each fringe in a window that has another one
> on the left gets overwritten by the "vertical window border".  With
> window dividers or scroll bars on, that border is not drawn.  I think we
> should remove that border completely and draw a one pixel wide window
> divider instead when scroll bars are disabled in a window and dividers
> are off.  Tricky because scroll bars can be turned off individually for
> windows and dividers are frame wide.  Strictly for Emacs 27.
>

Oh no, can this be please fixed in emacs 26.1? I am pretty sure that people
using emacs without scroll bars and without window dividers are not in
minority. This artifact will be pretty evident to people using fringe
elements like in diff-hl-mode.

@Eli: Can this be a blocker for 26.1?

As a workaround for things to come I suggest using a one pixel wide
> right only window divider with scroll bars off.
>

The workaround doesn't behave the same because now the windows have a white
line show up for the window dividers:

[image: image.png]

The "vertical window border" looks very much elegant IMO (with the window
dividers disabled, but that then truncates the fringe):

[image: image.png]

It this workaround is needed, then:
1) Would it be possible to customize the divider color?
2) It should also go in NEWS and /etc/PROBLEMS

The best case of course is if this can be fixed before 26.1 release.


> Both dumps are completely normal.
>

Should the dumps be updated with more info to help catch this?

Thanks!
-- 

Kaushal Modi

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