Fix crash in conf/etc. with empty optional values

core/color_codes.js

@@ -98,6 +98,9 @@ function ansiSgrFromCnetStyleColorCode(cc) {
 }
 
 function renegadeToAnsi(s, client) {
+    if (!s) {
+        return '';
+    }
     if (-1 == s.indexOf('|')) {
         return s; //  no pipe codes present
     }

core/string_util.js

@@ -45,6 +45,10 @@ const SIMPLE_ELITE_MAP = {
 };
 
 function stylizeString(s, style) {
+    if (!s) {
+        return '';
+    }
+
     var len = s.length;
     var c;
     var i;

core/text_view.js

@@ -153,7 +153,11 @@ TextView.prototype.setText = function (text, redraw) {
 
     if (!_.isString(text)) {
         //  allow |text| to be numbers/etc.
-        text = text.toString();
+        if (_.isUndefined(text) || null === text) {
+            text = '';
+        } else {
+            text = text.toString();
+        }
     }
 
     const formatObj = getPredefinedMCIFormatObject(this.client, text);