Motivation:
Currently, when passing custom headers to a WebSocketClientHandshaker,
if values are added for headers that are reserved for use in the
websocket handshake performed with the server, these custom values can
be used by the server to compute the websocket handshake challenge. If
the server computes the response to the challenge with the custom header
values, rather than the values computed by the client handshaker, the
handshake may fail.
Modifications:
Update the client handshaker implementations to add the custom header
values first, and then set the reserved websocket header values.
Result:
Reserved websocket handshake headers, if present in the custom headers
passed to the client handshaker, will not be propagated to the server.
Instead the client handshaker will propagate the values it generates.
Fixes#7973.
48911e0b63