id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
28081	django.test.client:conditional_content_removal() is not compliant with RFC7230	Ed Morley	João Silva	"[https://tools.ietf.org/html/rfc7230#section-3.3.2 RFC7230 section 3.3.2] says:
> A server MAY send a Content-Length header field in a 304 (Not Modified) response to a conditional GET request (Section 4.1 of [RFC7232]); a server MUST NOT send Content-Length in such a response unless its field-value equals the decimal number of octets that would have been sent in the payload body of a 200 (OK) response to the same request.
>
> A server MUST NOT send a Content-Length header field in any response with a status code of 1xx (Informational) or 204 (No Content).  A server MUST NOT send a Content-Length header field in any 2xx (Successful) response to a CONNECT request (Section 4.3.6 of [RFC7231]).

However `conditional_content_removal()` sets `Content-Type: 0` in these cases:
https://github.com/django/django/blob/941b8691351d4739cd9391b0a1326abd0b1c29c0/django/test/client.py#L91-L108

...which is not compliant with the specification.

The fix is to not set  `Content-Type` at all in `conditional_content_removal()`.

Note: After #26052 `conditional_content_removal()` is only used by the `django.test.client`, though that caused the regression #28054, for which the fix will be making runserver use it too."	Bug	closed	Testing framework	dev	Normal	fixed			Accepted	1	0	0	0	0	0