Merge branch 'ws/curl-http-proxy-over-https'

Git has been taught to support an https:// URL used for http.proxy
when using recent versions of libcurl.

* ws/curl-http-proxy-over-https:
http: support CURLPROXY_HTTPS

diff --combined http.c
index 215bebef1bfb935355a765027fc8605fccbc3d1b,9f98b56f221697a8613c2bd55a347ef92a173a05..32d33261c98cce2d5fd25c07a503654a3d5d2e52
--- 1/http.c
--- 2/http.c
+++ b/http.c
@@@ -12,7 -12,6 +12,7 @@@
  #include "gettext.h"
  #include "transport.h"
  #include "packfile.h"
 +#include "protocol.h"
  
  static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
  #if LIBCURL_VERSION_NUM >= 0x070a08
@@@ -865,6 -864,11 +865,11 @@@ static CURL *get_curl_handle(void
                else if (starts_with(curl_http_proxy, "socks"))
                        curl_easy_setopt(result,
                                CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
+ #endif
+ #if LIBCURL_VERSION_NUM >= 0x073400
+               else if (starts_with(curl_http_proxy, "https"))
+                       curl_easy_setopt(result,
+                               CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
  #endif
                if (strstr(curl_http_proxy, "://"))
                        credential_from_url(&proxy_auth, curl_http_proxy);
@@@ -899,21 -903,6 +904,21 @@@ static void set_from_env(const char **v
                *var = val;
  }
  
 +static void protocol_http_header(void)
 +{
 +      if (get_protocol_version_config() > 0) {
 +              struct strbuf protocol_header = STRBUF_INIT;
 +
 +              strbuf_addf(&protocol_header, GIT_PROTOCOL_HEADER ": version=%d",
 +                          get_protocol_version_config());
 +
 +
 +              extra_http_headers = curl_slist_append(extra_http_headers,
 +                                                     protocol_header.buf);
 +              strbuf_release(&protocol_header);
 +      }
 +}
 +
  void http_init(struct remote *remote, const char *url, int proactive_auth)
  {
        char *low_speed_limit;
@@@ -944,8 -933,6 +949,8 @@@
        if (remote)
                var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
  
 +      protocol_http_header();
 +
        pragma_header = curl_slist_append(http_copy_default_headers(),
                "Pragma: no-cache");
        no_pragma_header = curl_slist_append(http_copy_default_headers(),