fix error codes handling

MPD_ERROR_* and MPD_SERVER_ERROR_* flags can have the same
value, so we need to store it separately in error_code.

src/mpdpp.cpp

@@ -124,6 +124,7 @@ void MPD::Connection::SetHostname(const std::string &host)
 
 bool MPD::Connection::SendPassword()
 {
+	assert(itsConnection);
 	GoBusy();
 	assert(!isCommandsListEnabled);
 	mpd_run_password(itsConnection, itsPassword.c_str());
@@ -1297,8 +1298,8 @@ int MPD::Connection::CheckForErrors()
 		{
 			// this is to avoid setting too small max size as we check it before fetching current status
 			// setting real max playlist length is in UpdateStatus()
-			error_code = mpd_connection_get_server_error(itsConnection);
-			if (error_code == MPD_SERVER_ERROR_PLAYLIST_MAX && itsMaxPlaylistLength == size_t(-1))
+			error_code |= (mpd_connection_get_server_error(itsConnection) << 8);
+			if ((error_code >> 8) == MPD_SERVER_ERROR_PLAYLIST_MAX && itsMaxPlaylistLength == size_t(-1))
 				itsMaxPlaylistLength = 0;
 		}
 		if (!mpd_connection_clear_error(itsConnection))

src/status.cpp

@@ -191,7 +191,11 @@ void TraceMpdStatus()
 
 void NcmpcppErrorCallback(MPD::Connection *, int errorid, const char *msg, void *)
 {
-	if (errorid == MPD_SERVER_ERROR_PERMISSION)
+	// for errorid:
+	// - 0-7 bits define MPD_ERROR_* codes, compare them with (0xff & errorid)
+	// - 8-15 bits define MPD_SERVER_ERROR_* codes, compare them with (errorid >> 8)
+	
+	if ((errorid >> 8) == MPD_SERVER_ERROR_PERMISSION)
 	{
 		wFooter->SetGetStringHelper(0);
 		Statusbar() << "Password: ";