InvalidHeader exception when trying to add a ":method" header field (breaking change in 2.28.0) #6167
Description
My app is making a POST request enforcing some specific header fields. Among them, I was able to explicitly enforce a ":method" header field. But since 2.28.0, this now raises the following error:
requests.exceptions.InvalidHeader: Invalid leading whitespace, reserved character(s), or returncharacter(s) in header name: ':method'
Enforcing this header field is possibly a widespread practice as this is part of the requirements for sending notifications through Apple's push notification servers.