hi-res-thumbnails: cat thumbnail bug about scratchaddons

[WorldLanguages]

Why does this happen with only one project? I don't get it.

[OneShot-Niko]

can repro on LibreWolf
interestingly enough, console doesnt seem to throw any errors.

However, it does seem like the first four characters of the project ID are in the thumbnail part, but it only seems to happen with this project, which is odd.

[medlans]

Edit: Nevermind, I couldn't find this project before for some reason, but it does show the thumbnail for me, and I don't have that on.. I thought it might've been a Scratch thing because this has been happening without Scratch Addons in other places too
Browser: Chrome 125
Scratch Addons version: 1.38.2
Operating system: Mac OS 11.3 (Big Sur)

[mxmou]

Without the addon, the project ID in the image URL contains a slash:

[DNin01]

Those URLs are usually in this form:

https://uploads.scratch.mit.edu/get_image/project/10015857_144x108.png

On the front page right now, they are:

https://uploads.scratch.mit.edu/projects/thumbnails/10015857.png

Did they change recently, or have they always been like this?

With the second URL, you can put one slash anywhere between the digits and the image will still load.

https://uploads.scratch.mit.edu/projects/thumbnails/1/0015857.png
https://uploads.scratch.mit.edu/projects/thumbnails/10/015857.png
https://uploads.scratch.mit.edu/projects/thumbnails/100/15857.png
https://uploads.scratch.mit.edu/projects/thumbnails/1001/5857.png
https://uploads.scratch.mit.edu/projects/thumbnails/10015/857.png
https://uploads.scratch.mit.edu/projects/thumbnails/100158/57.png
https://uploads.scratch.mit.edu/projects/thumbnails/1001585/7.png

I'm not going to question why the front page uses different URLs, but this behavior is very weird. What causes that?

Hopefully this will just be a one-off thing that we don't have to worry about after this project is pushed off the front page, or at least happen infrequently enough to be a tolerable issue.

[DNin01]

It looks like we already handle URLs with the projects/thumbnails/ format and convert them to the get_image/ format¹, we just never expected to see URLs with a slash between the numbers. This shouldn't even happen in the first place.

Footnotes

1. https://github.com/ScratchAddons/ScratchAddons/blob/0da7e1c97052f0c02f4f03ff054374163d247fe2/addons/hi-res-thumbnails/userscript.js#L39-L53 ↩

[DNin01]

IMO, I wouldn't bother to solve this unless it happens a few more times.