Ticket #3372: 3372_3.patch

_source/plugins/undo/plugin.js

@@ -10 +10 @@
 
 (function()
 {
+        var modifierCodes = { 8:1, 46:1/*, 39:1, 40:1, 38:1, 37:1*/ };
         CKEDITOR.plugins.add( 'undo',
         {
                 requires : [ 'selection', 'wysiwygarea' ],
@@ -82 +83 @@
                                                                 {
                                                                         // Do not capture CTRL hotkeys.
                                                                         if ( !event.data.$.ctrlKey && !event.data.$.metaKey )
-                                                                                undoManager.type();
+                                                                                undoManager.type( event );
                                                                 });
 
                                                         // Being this the first call, let's get an undo snapshot.
@@ -182 +183 @@
                 this.index = -1;
 
                 this.limit = editor.config.undoStackSize;
+
+                /**
+                 * Remember last pressed key.
+                 */
+                this.lastKeystroke = 0;
         }
 
         UndoManager.prototype =
         {
-                type : function()
+                /**
+                 *
+                 * @param {CKEDITOR.dom.event} [event]
+                 */
+                type : function( event )
                 {
-                        if ( !this.typing )
+                        var keystroke = event && event.data.getKeystroke(),
+                                isModifier = keystroke in modifierCodes,
+                                lastWasSameModifier = isModifier && keystroke == this.lastKeystroke,
+                                modifierSnapshot = isModifier  && !lastWasSameModifier;
+                        
+                        if ( !this.typing || modifierSnapshot )
                         {
                                 var beforeTypeImage = new Image( this.editor );
 
@@ -219 +234 @@
                                                         this.onChange();
                                                 }
                                         },
-                                        0, this );
+                                        0, this
+                                );
 
-                                return;
+                                if ( !modifierSnapshot )
+                                        return;
                         }
 
                         this.typesCount++;
@@ -233 +250 @@
                         }
 
                         this.typing = true;
+                        this.lastKeystroke = keystroke;
                 },
 
                 fireChange : function()