section #connections is vague wrt connection is HTTP or HTTPS or HTTP/2 or QUIC

The obtain a connection algorithm in section #connections presently says this:

Set connection to the result of establishing an HTTP connection to origin. [HTTP] [HTTP-SEMANTICS] [HTTP-COND] [HTTP-CACHING] [HTTP-AUTH] [TLS]

If credentials is false, then do not send a TLS client certificate.

However, one is not going to "send a TLS client certificate" if one is not running over TLS, and there is no context in this alg whether or not a HTTP or HTTPS or HTTP/2 or QUIC or whatever connection is established.

Given the associated Note says in part: "This is intentionally a little vague as the finer points are still evolving." this is likely understood, tho I did not find an already-open issue regarding this, thus am submitting this one.

Offhand, it seems one way to nominally address this is to:

• declare a connectionType enum with values of "HTTP, HTTPS, HTTP/2, QUIC" (for now),
• pass a connectionType param to the obtain a connection algorithm,
• add connectionType as part of the per-connection state maintained by the connection pool
• add logic to obtain a connection alg to open conn of specific type per connectionType.

Read section #connections and the obtain a connection algorithm, including the associated Note and the referenced HTTP, TLS, and related specifications. Define how the connection type and per-connection state should be represented, then ensure the algorithm and TLS client-certificate behavior are no longer ambiguous.