nghttpx: Omit well-known port from hostport in downstream request

src/shrpx_http2_session.cc

@@ -506,6 +506,10 @@ int Http2Session::downstream_connect_proxy() {
 
   std::string req = "CONNECT ";
   req += downstream_addr.hostport.get();
+  if (downstream_addr.port == 80 || downstream_addr.port == 443) {
+    req += ":";
+    req += util::utos(downstream_addr.port);
+  }
   req += " HTTP/1.1\r\nHost: ";
   req += downstream_addr.host.get();
   req += "\r\n";

src/util.cc

@@ -1038,8 +1038,10 @@ std::string make_hostport(const char *host, uint16_t port) {
     hostport += "]";
   }
 
+  if (port != 80 && port != 443) {
     hostport += ":";
     hostport += utos(port);
+  }
 
   return hostport;
 }

src/util.h

@@ -609,7 +609,7 @@ std::string format_duration(const std::chrono::microseconds &u);
 
 // Creates "host:port" string using given |host| and |port|.  If
 // |host| is numeric IPv6 address (e.g., ::1), it is enclosed by "["
-// and "]".
+// and "]".  If |port| is 80 or 443, port part is omitted.
 std::string make_hostport(const char *host, uint16_t port);
 
 } // namespace util