Fix an IE11 crash.

diff --git a/www/js/remoteglot.js b/www/js/remoteglot.js
index 30f2d061dda1c9dcf0d217d1879f3b0052c68732..12b349ae151c236e4551e2b8ad8ccc13405878b9 100644 (file)
--- a/www/js/remoteglot.js
+++ b/www/js/remoteglot.js
@@ -252,7 +252,9 @@ var sync_server_clock = function(server_date_string) {
 var clear_arrows = function() {
        for (var i = 0; i < arrows.length; ++i) {
                if (arrows[i].svg) {
-                       arrows[i].svg.parentElement.removeChild(arrows[i].svg);
+                       if (arrows[i].svg.parentElement) {
+                               arrows[i].svg.parentElement.removeChild(arrows[i].svg);
+                       }
                        delete arrows[i].svg;
                }
        }
@@ -367,7 +369,9 @@ var point_from_end = function(x1, y1, x2, y2, t, u) {
 
 var position_arrow = function(arrow) {
        if (arrow.svg) {
-               arrow.svg.parentElement.removeChild(arrow.svg);
+               if (arrow.svg.parentElement) {
+                       arrow.svg.parentElement.removeChild(arrow.svg);
+               }
                delete arrow.svg;
        }
        if (current_display_line !== null && !current_display_line_is_history) {