Bug overview description.
Unexpected response when calling post/create with no parameters

I guess it doesn't impair any functionality but you might want to look into that

What part(s) of the site page(s) are affected?
API, post/create

What is the expected behavior?
error + json/xml response

What actual behavior is given instead?
302 with HTML response

Location is set to something that looks like a ruby error

https://e621.net/post/show?id=%23%3CProc%3A0x000000040f6618%40%2Fhome%2Fe621%2Fe621-production%2Freleases%2F20160126060000%2Fapp%2Fcontrollers%2Fpost_controller.rb%3A15+%28lambda%29%3E

Following the redirect leads to an HTML page

Time of incident (if applicable).
N/A

Can you reproduce the bug every time?
Yes

What steps did you take to replicate this bug?
Make an empty request to https://e621.net/post/create.xml or https://e621.net/post/create.json

Errors or other messages returned (if any).
No errors

Duplicate of internal bug ID #420.

https://e621.net/forum/show/201659