[MRG+1] response_status_message should not fail on non-standard HTTP codes

[pawelmhm]

utility is used in retry middleware and it was failing to handle non-standard HTTP codes. Instead of raising exceptions when passing through to_native_str it should return "Unknown status" message.

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[redapple]

Quoting RFC 7231, section 6

a client MUST (...) treat an unrecognized status code as being equivalent to the x00 status code of that class

so I suggest we use reason phrases from their class "x00" status code.
For classes above 5 (like in '999 Request Denied'), if reason is missing, I prefer using "Unknown Reason" instead of "Unknown Status"

[pawelmhm]

so I suggest we use reason phrases from their class "x00" status code.
For classes above 5 (like in '999 Request Denied'), if reason is missing, I prefer using "Unknown Reason" instead of "Unknown Status"

this utility should actually handle all status codes which are not HTTP standard compliant, so some theoretical status code 391 or 254 or even some status 12900 as well. The way it currently works is that it doesn't check if status is from 4** or 5** range. Are you suggesting we should handle invalid statuses from different classes in different ways? It would add some complexity to handle differences between invalid status codes in 3xx or 4xx or 5xx ranges. Or are you saying that "Unknown Reason" is just better message for all possible invalid HTTP status codes?

EDIT:

BTW I've chosen "Unknown Status" because it follows Twisted convention http://twistedmatrix.com/trac/browser/tags/releases/twisted-16.0.0/twisted/web/http.py#L1035

[redapple]

@pawelmhm , I was suggesting to use 200, 300, 400, 500 reasons for their respective classes and "Unknown Reason" for invalid classes.
But it's probably more cosmetic than anything as I doubt many people look at reason message

[redapple]

I just realized that the actual reason is not available in the response.

[kmike]

I liked doctest more because it is useful as documentation, not only as a test.
But feel free to merge it.

[mtwilliams]

Just ran into this! 💯