Merge branch 'ew/keepalive'

* ew/keepalive:
http: use curl's tcp keepalive if available
http: enable keepalive on TCP sockets

diff --cc http.c
index f3e1439d58a00328ece38a6eead63309fe7f58ca,635952619619aa057e51eef4b25bd1651e3da46b..0ddb164a6f239789664c77f1dd97a31086fc71e3
--- 1/http.c
--- 2/http.c
+++ b/http.c
@@@ -249,17 -219,56 +249,53 @@@ static void init_curl_http_auth(CURL *r
  
  static int has_cert_password(void)
  {
 -      if (ssl_cert_password != NULL)
 -              return 1;
        if (ssl_cert == NULL || ssl_cert_password_required != 1)
                return 0;
 -      /* Only prompt the user once. */
 -      ssl_cert_password_required = -1;
 -      ssl_cert_password = git_getpass("Certificate Password: ");
 -      if (ssl_cert_password != NULL) {
 -              ssl_cert_password = xstrdup(ssl_cert_password);
 -              return 1;
 -      } else
 -              return 0;
 +      if (!cert_auth.password) {
 +              cert_auth.protocol = xstrdup("cert");
 +              cert_auth.username = xstrdup("");
 +              cert_auth.path = xstrdup(ssl_cert);
 +              credential_fill(&cert_auth);
 +      }
 +      return 1;
  }
  
+ #if LIBCURL_VERSION_NUM >= 0x071900
+ static void set_curl_keepalive(CURL *c)
+ {
+       curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
+ }
+ 
+ #elif LIBCURL_VERSION_NUM >= 0x071000
+ static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
+ {
+       int ka = 1;
+       int rc;
+       socklen_t len = (socklen_t)sizeof(ka);
+ 
+       if (type != CURLSOCKTYPE_IPCXN)
+               return 0;
+ 
+       rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
+       if (rc < 0)
+               warning("unable to set SO_KEEPALIVE on socket %s",
+                       strerror(errno));
+ 
+       return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
+ }
+ 
+ static void set_curl_keepalive(CURL *c)
+ {
+       curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
+ }
+ 
+ #else
+ static void set_curl_keepalive(CURL *c)
+ {
+       /* not supported on older curl versions */
+ }
+ #endif
+ 
  static CURL *get_curl_handle(void)
  {
        CURL *result = curl_easy_init();
@@@ -322,16 -331,11 +358,18 @@@
        if (curl_ftp_no_epsv)
                curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
  
 -      if (curl_http_proxy)
 +#ifdef CURLOPT_USE_SSL
 +      if (curl_ssl_try)
 +              curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 +#endif
 +
 +      if (curl_http_proxy) {
                curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 +              curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 +      }
  
+       set_curl_keepalive(result);
+ 
        return result;
  }