Yahoo login doesn't seem to work

[supermathie (Michael Brown)]

The root cause of this problem (502 from nginx) has been identified and a fix is underway:

Yahoo login for Discourse

It does make a difference, actually. The actual problem was that in our environment the size of the headers sent back by Discourse for the request going to /auth/yahoo are very large - 3897 bytes. BUT when navigating around before trying to login, the headers (one of which is the cookie that has some pre-login session state) gets larger, e.g. up to a size of 4142 bytes. This is larger than the buffer which nginx allocates for holding that first part of the response. Upping the size of proxy_…