Ticket #8226: 8226_5.patch

_source/core/dom/element.js

@@ -1479 +1479 @@
                                 }
                         }
 
-                        return $ && new CKEDITOR.dom.document( $.contentWindow.document );
+                        return $ && $.contentWindow && new CKEDITOR.dom.document( $.contentWindow.document );
                 },
 
                 /**
@@ -1580 +1580 @@
                         return this.$.childNodes.length;
                 },
 
+                /**
+                 *  Whether this element is not present in the DOM tree.
+                 */
+                isOffline : function()
+                {
+                        var root = this.getDocument().getDocumentElement();
+                        return !root.contains( this );
+                },
+
                 disableContextMenu : function()
                 {
                         this.on( 'contextmenu', function( event )

_source/core/editor.js

@@ -465 +465 @@
                                                 || getNewName();
 
                         if ( this.name in CKEDITOR.instances )
-                                throw '[CKEDITOR.editor] The instance "' + this.name + '" already exists.';
+                        {
+                                var previous = CKEDITOR.instances[ this.name ];
 
+                                // Destroy detached editor silently.
+                                if ( previous.element.isOffline() || previous.container && previous.container.isOffline() )
+                                        previous.destroy( false );
+                                else
+                                        throw '[CKEDITOR.editor] The instance "' + previous.name + '" already exists.';
+                        }
+
                         /**
                          * A unique random string assigned to each editor instance on the page.
                          * @name CKEDITOR.editor.prototype.id

_source/plugins/wysiwygarea/plugin.js

@@ -1032 +1032 @@
                                                                         xmlDeclaration = fullPage && editor.xmlDeclaration,
                                                                         doc = iframe.getFrameDocument();
 
+                                                                if ( !doc )
+                                                                        return null;
+
                                                                 var data = fullPage
                                                                         ? doc.getDocumentElement().getOuterHtml()
                                                                         : doc.getBody().getHtml();