Implemented disabled save button when already saved

src/editor/js/components/historynavigator.tsx

@@ -82,7 +82,16 @@ export class HistoryNavigator extends React.Component<propTypes> {
                           })
                         : ""}
                 </select>
-                <button onClick={this.handleSave}>Save</button>
+                <button
+                    onClick={this.handleSave}
+                    disabled={
+                        this.props.historyObject
+                            ? !this.props.historyObject.hasUnsavedChanges()
+                            : true
+                    }
+                >
+                    Save
+                </button>
             </div>
         );
     }