[26.3] large image scrolling gets stuck

[26.3] large image scrolling gets stuck

[dick.r.chiang]

SPC is `gnus-summary-next-page` from the summary buffer.  If the article
contains a large image, SPC stops scrolling upon hitting the image.

The image is miraculously scaled down in both emacs-26.2 and emacs-27.0.50,
deftly avoiding this bug.

Hoping Mr. Ingebrigtsen sees this; I imagine he would immediately know why
this is.

Re: [26.3] large image scrolling gets stuck

[Eric S Fraga]

On Wednesday,  9 Oct 2019 at 20:38, dick.r.chiang@gmail.com wrote:
> SPC is `gnus-summary-next-page` from the summary buffer.  If the article
> contains a large image, SPC stops scrolling upon hitting the image.

Just to add that I see this as well.  If the image is larger than the
window, possibly in either dimension, scrolling doesn't happen.

-- 
Eric S Fraga via Emacs 27.0.50 & org 9.2.4 on Debian bullseye/sid

Re: [26.3] large image scrolling gets stuck

[Eric Abrahamsen]

Eric S Fraga <e.fraga@ucl.ac.uk> writes:

> On Wednesday,  9 Oct 2019 at 20:38, dick.r.chiang@gmail.com wrote:
>> SPC is `gnus-summary-next-page` from the summary buffer.  If the article
>> contains a large image, SPC stops scrolling upon hitting the image.
>
> Just to add that I see this as well.  If the image is larger than the
> window, possibly in either dimension, scrolling doesn't happen.

My understanding is that this is a general problem with image display in
Emacs, nothing particular to Gnus. Something about how Emacs calculates
line heights when scrolling -- maybe images are calculated to fit on a
single really tall line, so you can only scroll all the way past them?
Something like that.

Re: [26.3] large image scrolling gets stuck

[dick]

Yes, that sounds right.  Would be nice to get confirmation on 26.2 and 27.050
not exhibiting this bug.

Re: [26.3] large image scrolling gets stuck

[Eric Abrahamsen]

dick <dick.r.chiang@gmail.com> writes:

> Yes, that sounds right.  Would be nice to get confirmation on 26.2 and 27.050
> not exhibiting this bug.

I think all versions have this behavior -- no one has implemented
sub-line scrolling yet.

Re: [26.3] large image scrolling gets stuck

[dick]

I'm referring to the descaled images in the versions straddling emacs 26.3.
For whatever reason, 26.3 shows a bigger image than 26.2 and 27.0.50.

Re: [26.3] large image scrolling gets stuck

[Eric Abrahamsen]

dick <dick.r.chiang@gmail.com> writes:

> I'm referring to the descaled images in the versions straddling emacs 26.3.
> For whatever reason, 26.3 shows a bigger image than 26.2 and 27.0.50.

Oh, I don't know, then -- maybe that's something you'd want to raise on
emacs.devel.

Re: [26.3] large image scrolling gets stuck

[Andreas Schwab]

On Okt 10 2019, dick <dick.r.chiang@gmail.com> wrote:

> I'm referring to the descaled images in the versions straddling emacs 26.3.

If you want image scaling in emacs < 27 you need ImageMagick.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: [26.3] large image scrolling gets stuck

[dick]

Somehow a local deinstall of imagemagick (IM) coincided with my compile of
emacs-26.3 leading me to believe image descaling broke in 26.3.  Sorry,
nothing to see here.

In my opinion, Gnus is unusable without IM's descaling, and so is
unusable for a big chunk of users whose systems lack IM libraries.  I hear
murmurs of emacs's emancipation from IM, which seems key if Gnus is to reach
a wider audience.