Difference between older images and recent images

Following a link to the url of an image uploaded to Codidact redirects to an AWS link for recently uploaded images. For older images, following the link instead starts a file download. On desktop this downloaded file opens as an image, but on mobile the downloaded file is not recognised as an image and will not open. On Firefox for Android this results in an incorrect file type being guessed (there is an automatically appended .bin in the filename) while on Chrome for Android no file extension is added. In both cases the file will not open.

The example image links are taken from Meta posts. For convenience I have edited both posts so that in each case the image is a link to the standalone image. This means you can click the image on desktop or tap the image on mobile and it will open the standalone image.

Note that clicking or tapping an image in most Codidact posts will have no effect. In those cases you can get a link by right clicking/long pressing and selecting "Copy Image Link". Exact wording may vary between browsers.

Recent Meta post

• Automatically added redundant markdown when editing tags

Older Meta post

• Move keyboard focus into the search term box when search is clicked

Redirect with recent images

Clicking/tapping the image or pasting the URL of the image into a new browser tab (desktop or mobile) results in being redirected to a new URL, which displays the image in the browser.

Original URL

https://meta.codidact.com/uploads/3sifm64vlhqhz84vk97lkbu6kl8a

Redirected URL

https://s3.amazonaws.com/storage.codidact.com/3sifm64vlhqhz84vk97lkbu6kl8a

Download with older images

Clicking/tapping the image or pasting the URL of the image into a new browser tab (desktop or mobile) results in a file being downloaded.

URL

https://meta.codidact.com/uploads/gl22tann626tcy50n0mq340osonb

Filename on Firefox for desktop

gl22tann626tcy50n0mq340osonb

Filename on Firefox for Android

gl22tann626tcy50n0mq340osonb.bin

Note the .bin extension that has been added on mobile. My mobile gives an error message saying it has no app to open .bin files. Renaming the file to remove to .bin still results in my mobile being unable to display the image.

(Note that as mentioned, Chrome for Android does not add a file extension, but is also unable to display the image.)

Renaming the file to have an extension of either .png or .jpg (at least one of which must be incorrect) results in my mobile displaying the image correctly. The fact that it can display the image correctly even with an incorrect image file extension suggests that it is getting the image type (PNG or JPEG) from the file content, rather than from the file extension. It just seems to struggle when there is no extension or a non-image extension such as .txt.

posted 10 months ago

CC BY-SA 4.0

7mo ago

trichoplax‭

176 60 575 254