Re: Fill column indicator functionality

[Ergus]

On Fri, Apr 05, 2019 at 11:10:15AM +0200, Robert Pluim wrote:
> > > > > > On Wed, 03 Apr 2019 14:11:00 +0300, Eli Zaretskii <address@hidden> said:
>
>    Eli> The changes you made look fine to me.  Let's wait for more
>    Eli> people to try the branch.
>
> Iʼve just tried it.
>
> - etc/NEWS says:
>
>    Customize the buffer-local variables 'display-fill-column-indicator'
>
> but M-x customize-variable doesnʼt know about
> 'display-fill-column-indicator'
Hi:

Sorry, I forgot to add it to cus-start.el I fixed right now. Ween I set
the variable with set-variable it works for me. (and redisplay is called)

The problem now is that I added it to cus-start.el but when I set it
with the interface, the line does not change at all. Nothing really
happens when I save.

Could anyone tell me what I am missing here please??

> - the manual talks about 'global-display-fill-column-indicator-mode', but
> M-x doesnʼt  know about that function until I
>    (require 'display-fill-column-indicator)
> (this may be due to the way autoloads work in emacs. Thereʼs an entry
> in ldefs-boot.el for it)
I have it without the require, so maybe when generating the autoload
(which seems to be an automatic process) it will appear. 

> - the Commentary section in display-fill-column-indicator.el still
> talks about line numbers, and appears truncated.
Fixed, thanks!

> - when I turn it on, it chooses \u2502, which is not displayable by my
> default font, but is displayable by a fallback font. I end up with
> empty blocks at the end of each line. I can probably customize
> 'fill-column-face' to work around this, but Iʼd expect this to work by
> default (either by using '|' or using the fallback font).
I don't really find a right method to fix this because the
char-displayable-p function seems not to be accurate in many
cases. There was a discussion about this before, but there was not a
final agreement I think. And from the char-displayable-p documentation:

```
On a multi-font display, the test is only whether there is an
appropriate font from the selected frame's fontset to display
CHAR's charset in general.  Since fonts may be specified on a
per-character basis, this may not be accurate.
```

Any suggestion here?

> - in org-mode buffers the indicator is displayed as '['. This may be
> related to the previous point (those buffers use yet a third font).

> Robert

Ergus