bug#58373: Support image-type `jpg'

bug#58373: Support image-type `jpg'

[Thuna]

Currently, `jpg' is not in image-types, despite `jpeg' being in it.
Similarly, image descriptors of the form `(image :type jpg...)' do not
display properly, while those of the form `(image :type jpeg...)' do.

Changing the type from jpg to jpeg (for a jpg image) does display the
image, so it's not like Emacs is incapable of doing it; I imagine this
should be a trivial fix.

bug#58373: Support image-type `jpg'

[Stefan Kangas]

Thuna <thuna.cing@gmail.com> writes:

> Currently, `jpg' is not in image-types, despite `jpeg' being in it.
> Similarly, image descriptors of the form `(image :type jpg...)' do not
> display properly, while those of the form `(image :type jpeg...)' do.

The image type is really "JPEG" (and the MIME type "image/jpeg"), while
".jpg" just happens to be a commonly used file extension for that file
format.  So what we have now is already correct, strictly speaking.

All the same, perhaps it would be convenient to allow "jpg" as an alias
for "jpeg".  Would that risk introducing some backwards-incompatibility
with some package out there though?

bug#58373: Support image-type `jpg'

[Lars Ingebrigtsen]

Stefan Kangas <stefankangas@gmail.com> writes:

> The image type is really "JPEG" (and the MIME type "image/jpeg"), while
> ".jpg" just happens to be a commonly used file extension for that file
> format.  So what we have now is already correct, strictly speaking.
>
> All the same, perhaps it would be convenient to allow "jpg" as an alias
> for "jpeg".  Would that risk introducing some backwards-incompatibility
> with some package out there though?

It probably won't, but I don't think it would be a good idea to
introduce an alias here.  It's less confusing to just have a simple
single mapping from type to backend.

So I don't think we should do anything here, and I'm therefore closing
this bug report.