Ticket #4673: 4673_2.patch

_source/plugins/undo/plugin.js

@@ -179 +179 @@
                 this.reset();
         }
 
+
+        var editingKeyCodes = { /*Backspace*/ 8:1, /*Delete*/ 46:1 },
+                modifierKeyCodes = { /*Shift*/ 16:1, /*Ctrl*/ 17:1, /*Alt*/ 18:1 },
+                navigationKeyCodes = { 37:1, 38:1, 39:1, 40:1 };  // Arrows: L, T, R, B
+
         UndoManager.prototype =
         {
                 /**
@@ -187 +192 @@
                  */
                 type : function( event )
                 {
-                        var keystroke = event && event.data.getKeystroke(),
-
-                                // Backspace, Delete
-                                modifierCodes = { 8:1, 46:1 },
-                                // Keystrokes which will modify the contents.
-                                isModifier = keystroke in modifierCodes,
-                                wasModifier = this.lastKeystroke in modifierCodes,
-                                lastWasSameModifier = isModifier && keystroke == this.lastKeystroke,
-
-                                // Arrows: L, T, R, B
-                                resetTypingCodes = { 37:1, 38:1, 39:1, 40:1 },
+                        var keystroke = event && event.data.getKey(),
+                                isModifierKey = keystroke in modifierKeyCodes,
+                                isEditingKey = keystroke in editingKeyCodes,
+                                wasEditingKey = this.lastKeystroke in editingKeyCodes,
+                                sameAsLastEditingKey = isEditingKey && keystroke == this.lastKeystroke,
                                 // Keystrokes which navigation through contents.
-                                isReset = keystroke in resetTypingCodes,
-                                wasReset = this.lastKeystroke in resetTypingCodes,
+                                isReset = keystroke in navigationKeyCodes,
+                                wasReset = this.lastKeystroke in navigationKeyCodes,
 
                                 // Keystrokes which just introduce new contents.
-                                isContent = ( !isModifier && !isReset ),
+                                isContent = ( !isEditingKey && !isReset ),
 
                                 // Create undo snap for every different modifier key.
-                                modifierSnapshot = ( isModifier && !lastWasSameModifier ),
+                                modifierSnapshot = ( isEditingKey && !sameAsLastEditingKey ),
                                 // Create undo snap on the following cases:
-                                // 1. Just start to type.
+                                // 1. Just start to type .
                                 // 2. Typing some content after a modifier.
                                 // 3. Typing some content after make a visible selection.
-                                startedTyping = !this.typing
-                                        || ( isContent && ( wasModifier || wasReset ) );
+                                startedTyping = !( isModifierKey || this.typing )
+                                        || ( isContent && ( wasEditingKey || wasReset ) );
 
                         if ( startedTyping || modifierSnapshot )
                         {
@@ -250 +249 @@
                         }
 
                         this.lastKeystroke = keystroke;
+
+                        // Ignore modifier keys. (#4673)
+                        if( isModifierKey )
+                                return;
                         // Create undo snap after typed too much (over 25 times).
-                        if ( isModifier )
+                        if ( isEditingKey )
                         {
                                 this.typesCount = 0;
                                 this.modifiersCount++;