Ticket #8226: 8226_2.patch

_source/core/dom/element.js

@@ -1479 +1479 @@
                                 }
                         }
 
-                        return $ && new CKEDITOR.dom.document( $.contentWindow.document );
+                        return $ && $.contentWindow && new CKEDITOR.dom.document( $.contentWindow.document );
                 },
 
                 /**

_source/core/editor.js

@@ -465 +465 @@
                                                 || getNewName();
 
                         if ( this.name in CKEDITOR.instances )
-                                throw '[CKEDITOR.editor] The instance "' + this.name + '" already exists.';
+                        {
+                                // Check if the editor has been removed from the DOM
+                                var previous = CKEDITOR.instances[ this.name ],
+                                        container = previous.container.$;
+                                while ( container && container!=document.body )
+                                        container = container.parentNode;
 
+                                // If it isn't in the document DOM, destroy it silently
+                                if ( !container )
+                                        previous.destroy( false );
+                                else
+                                        alert( '[CKEDITOR.editor] The instance "' + this.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();