... thumbnails.
A good example of the difference in behaviour of the PageImages API is
here <T156800#3087507>. The API defers to File#transform, which scales
the largest dimension of an image, not always the width, e.g. if an
image is 1000px x 2000px and the request is for a thumbnail "of 1800px",
then the thumbnail will be 900px x 1800px.
Bug: T156800
Change-Id: I64bc2244ee78a594298d8637233b0da1083700eb
If the image isn't an SVG then it shouldn't be scaled past its original
dimensions. Handle the case where the requested thumbnail can't be
generated on the server as the original is too small ( < 320px,
currently [0]) in the same way.
Moreover, if the image happens to have the exact dimensions that we're
requesting (300px or 600px wide, currently [1]), then use the original
image to avoid unnecessary work/pressure on caches.
Supporting changes:
* Update the SVG_RESTBASE_RESPONSE fixture to use the extension returned
by RESTBase (and the PageImages extension) for the thumbnail:
.svg.png.
[0] https://github.com/wikimedia/restbase/blob/master/v1/summary.yaml#L121
[1] https://github.com/wikimedia/mediawiki-extensions-Popups/blob/master/src/constants.js#L2
Bug: T156800
Change-Id: I5d0aa161e80869e4b4f5425d906d1e753047a3a3
Rather than manipulating the URL of the original image to get the URL of
the appropriately sized thumbnail, manipulate the URL of the thumbnail
image.
While we could manipulate either the thumbnail or original image URL,
there are subtle differences between the two, so manipulating the latter
makes the generateThumbnailData function as simple as possible, e.g. we
don't have to splice in "/thumb" after "/commons".
Also, ensure that the thumbnail's dimensions are scaled appropriately.
Bug: T156800
Change-Id: I6825bad14b1131dc81f23dcf120cf8ffb7d7b4f6
