400 status code for a regular GET request

Hi Здравко, Greg-DB and sorry for the late response. Today I finally managed to understand the root cause of the issue and found a workaround to it. It is not related to the extra new line I thought earlier, but it is something with the redirect URL received after the first GET request. I was a bit confused by the automatic redirects everywhere so the actual error was tied to the second request. Below are my test scenario, issue description and a workaround.

Test scenario:

1. Send a GET request to this URL: https://www.dropbox.com/scl/fi/fc5rwkff82yvy66ktagv7/test.txt?rlkey=wqzs2qbbfazbgj3ttcaik9pq2&dl=1

2. Receive a 302 Found response with this header: Location: https://ucf3d30d8449d3b4b71630f2179a.dl.dropboxusercontent.com/cd/0/get/CUfGJ4UYzNP3f_SeeyAWDmkzqSHoJk98QNNmD7g4NUoVFnAS6PpVPrCmKLfGBS9_fNsxCkcNG3dT40ygtSc8ceWPxLQYy-NiCrRMDxJ-5u_ZftDOnRmXk-ta_m1czPFq5KRSEvknl3F7pFjk01onJrqL/file?dl=1#

3. Follow the redirect URL and get a 400 Bad Request response. Note: the URL above expires quite early, it'll return the 410 response now, but it is expected and not the actual issue.

Issue and workaround:

The redirect URL contains the # character at the end which causes the 400 response. It is interesting that both curl and Postman remove this character so that is why it is not reproduced there. Removing this character manually before following the redirect fixes the issue and I can get a valid response in my environment as well.

Not sure why this character is a part of the URL and if it is an HTTP rule, Dropbox bug or bug of the underlaying library I'm using, but at least now I have a clean understanding of the issue and a workaround for it. I want to know your thoughts about it and then if it is a library bug, I'll redirect it to its developer 🙂