Fix up concat of undefined stdout/stderr. Hopefully addresses #163

static/compiler.js

@@ -291,7 +291,7 @@ define(function (require) {
             }
         }, this));
         var status = this.domRoot.find(".status");
-        var allText = _.pluck(result.stdout.concat(result.stderr), 'text').join("\n");
+        var allText = _.pluck((result.stdout || []).concat(result.stderr | []), 'text').join("\n");
         var failed = result.code !== 0;
         var warns = !failed && !!allText;
         status.toggleClass('error', failed);

static/editor.js

@@ -260,7 +260,7 @@ define(function (require) {
     };
 
     Editor.prototype.onCompileResponse = function (compilerId, compiler, result) {
-        var output = result.stdout.concat(result.stderr);
+        var output = (result.stdout || []).concat(result.stderr || []);
         var self = this;
         this.removeWidgets(this.widgetsByCompiler[compilerId]);
         var widgets = [];