Ticket #4552: 4552_3.patch

_source/core/tools.js

@@ -189 +189 @@
                         return ( !!object && object instanceof Array );
                 },
 
+                isEmpty : function ( object )
+                {
+                        for ( var i in object )
+                        {
+                                if ( object.hasOwnProperty( i ) )
+                                        return false;
+                        }
+                        return true;
+                },
                 /**
                  * Transforms a CSS property name to its relative DOM style name.
                  * @param {String} cssName The CSS property name.

_source/plugins/floatpanel/plugin.js

@@ -39 +39 @@
                                 });
                 }
 
+                panel.editor = editor;
                 return panel;
         }
 
@@ -55 +56 @@
 
                         this.element = element;
 
-                        // Register panels to editor for easy destroying ( #4241 ).
-                        editor.panels ? editor.panels.push( element ) : editor.panels = [ element ];
-
-
                         this._ =
                         {
                                 // The panel that will be floating.
@@ -329 +326 @@
                         }
                 }
         });
+
+        CKEDITOR.on( 'instanceDestroyed', function( evt )
+        {
+                var editor = evt.data,
+                        isLastInstance = CKEDITOR.tools.isEmpty( CKEDITOR.instances );
+
+                for( var i in panels )
+                {
+                        var panel = panels[ i ];
+                        // Safe to destroy it since there're no more instances.(#4241)
+                        if( isLastInstance )
+                        {
+                                panels[ i ].destroy();
+                                delete panels[ i ];
+                        }
+                        // Panel might be used by other instances, just hide them.(#4552)
+                        else if ( panel.editor == editor )
+                                panel.element.hide();
+                }
+        } );
 })();

_source/plugins/panel/plugin.js

@@ -230 +230 @@
                 block.show();
 
                 return block;
+        },
+
+        destroy : function()
+        {
+                this.element && this.element.remove();
         }
 };
 

_source/themes/default/theme.js

@@ -155 +155 @@
 
                 destroy : function( editor )
                 {
-                        var container = editor.container,
-                                panels = editor.panels;
+                        var container = editor.container;
 
                         /*
                          * IE BUG: Removing the editor DOM elements while the selection is inside
@@ -183 +182 @@
                         if ( container )
                                 container.remove();
 
-                        for( var i = 0 ; panels && i < panels.length ; i++ )
-                                        panels[ i ].remove();
-
                         if ( editor.elementMode == CKEDITOR.ELEMENT_MODE_REPLACE )
                         {
                                 editor.element.show();

_source/core/editor.js

@@ -467 +467 @@
                         this.theme.destroy( this );
                         this.fire( 'destroy' );
                         CKEDITOR.remove( this );
+                        CKEDITOR.fire( 'instanceDestroyed', this );
                 },
 
                 /**