Re: master a876c4d7a17: Improve SHR/EWW support for 'visual-wrap-prefix-mode'

[Jim Porter <jporterbugs@gmail.com>]

On 8/21/2024 10:50 AM, Kévin Le Gouguec wrote:
> Eshel Yaron <me@eshelyaron.com> writes:
> 
>> Hello Jim,
>>
>> Jim Porter <jporterbugs@gmail.com> writes:
>>
>>> branch: master
>>> commit a876c4d7a17df152e3e78800c76ddf158f632ee5
>>> Author: Jim Porter <jporterbugs@gmail.com>
>>> Commit: Jim Porter <jporterbugs@gmail.com>
>>>
>>>      Improve SHR/EWW support for 'visual-wrap-prefix-mode'
>>>      
>> [...]
>>
>> Thanks for this!
>>
>> It seems like this change breaks Elfeed though, namely:
[snip]
>> This call to font-at throws an error unless the current buffer happens
>> to be displayed in the selected window.  This affects elfeed-show-entry,
>> for example.

Thanks for noticing this. It'd be good to make the "get the average 
width of the font" bit work properly in all cases.

That said, this is *also* a bug in Elfeed. SHR just works a lot better 
if the buffer is displayed in a window before rendering the HTML out. 
See <https://github.com/skeeto/elfeed/pull/521>.

> diff --git a/lisp/visual-wrap.el b/lisp/visual-wrap.el
> index 902a9e41c5e..975ccab3adb 100644
> --- a/lisp/visual-wrap.el
> +++ b/lisp/visual-wrap.el
> @@ -164,7 +164,8 @@ visual-wrap--content-prefix
>       ;; width of the first-line prefix in canonical-width characters.
>       ;; This is useful if the first-line prefix uses some very-wide
>       ;; characters.
> -    (if-let ((font (font-at position))
> +    (if-let ((window (get-buffer-window (current-buffer)))
> +             (font (font-at position window))
>                (info (query-font font)))
>           (max (string-width prefix)
>                (ceiling (string-pixel-width prefix (current-buffer))

Assuming this is working for you, I think this patch makes sense and you 
can feel free to merge it.