curl: CURLOPT_PROXYHEADER is not part of the HTTP-proxy connection reuse key: a second CONNECT-tunnel transfer silently reuses the first tunnel's Proxy-Auth

Summary When libcurl tunnels through an HTTP proxy with CONNECT HTTPS-over-proxy, the custom headers set via CURLOPTPROXYHEADER are sent to the proxy once, at tunnel-setup time lib/httpproxy.c:63-83. The connection-reuse decision for a proxied connection, however, does not take proxyheaders into...