Some images uploaded in chat cannot be visited via the link

Question

This is an intermittent failure and I cannot find a good way to reliably reproduce it.

Some times when uploading an image in chat it shows up but the link leads to a page that says "oh no, that request didn't look right".

Here is an example of such a message - the image embeds and shows up, but clicking on it goes to https://i.sstatic.net/kEIRuMK.png and shows an error.

The exact steps¹ I took were:

1. Take a screenshot using the Greenshot software
2. Then used the option in Greenshot option to upload to Imgur
3. Then I opened the chat image uploader, switched to "from the web" and pasted the link for the Imgur image I got in step 2.

When I realised the link did not work, I used the exact same image (it was still open in Greenshot editor) and uploaded it through the main site, took the link, and posted it in chat: this is the resulting message (links to https://i.sstatic.net/Cbs8ZxZr.png) and it both embeds and the link shows the image.

Here is another message from a different user exhibiting the same problem - it embeds but the link is dead. The link to the image is https://i.sstatic.net/VgpSV1t.png This was uploaded using a chat extension but essentially used a local image (like how the "from my computer" option works) instead of using an image link from the web.

I cannot guarantee only images that go through the chat uploader experiences this problem. So far, I have only observed it in chat. Moreover, does not seem to happen consistently.

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¹ I am including the steps for completeness. I do not believe anything specifically in these steps triggers the behaviour.

Answer 1

This was inadvertently broken when we upgraded chat to use the new image service. Copying from my comment:

Ohhhhh - I know what's happening. The actual image is https://i.sstatic.net/kEIRuMKb.png. Note that the filename is 8 characters long (new image service) and also note that it ends in a b. Chat tries to do this clever thing where if someone uploads an image thumbnail (with a trailing letter resize s,ml,b,t,h), it'll use the provided image in chat, but link to the full image (by stripping off the trailing resize char). In this case, because the random image id happened to end in b (thus why it randomly happens) chat removes it thinking it's linking to the full image.

I updated the parsing in OneBoxes to be more specific about image lengths when looking for a trailing resize character:

- ^(https?://i\.sstatic\.net/)([^.]+?)(s|b|t|m|l|h)?(\..*)$
+ ^(https?://i\.sstatic\.net/)([^.]{5}|[^.]{8})(s|b|t|m|l|h)?(\..*)$

Caveat: I didn't go back in and re-bake the old one-boxes that had already parsed the message contents. Going forward, this will be fixed, but old messages you'll have to continue to workaround if you're trying to click on image links (Right click > Copy image address)