Index: /CKEditor/branches/versions/3.4.x/CHANGES.html
===================================================================
--- /CKEditor/branches/versions/3.4.x/CHANGES.html	(revision 5572)
+++ /CKEditor/branches/versions/3.4.x/CHANGES.html	(revision 5573)
@@ -41,4 +41,5 @@
 	<ul>
 		<li><a href="http://dev.fckeditor.net/ticket/5628">#5628</a> : Port 'DragResizeTable' plugin from FCKEditor 2.x.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/979">#979</a> : New configuration 'enableTabKeyTools' to allow using 'Tab' key to navigate through table cells.</li>
 	</ul>
 	<p>
Index: /CKEditor/branches/versions/3.4.x/_source/plugins/tab/plugin.js
===================================================================
--- /CKEditor/branches/versions/3.4.x/_source/plugins/tab/plugin.js	(revision 5572)
+++ /CKEditor/branches/versions/3.4.x/_source/plugins/tab/plugin.js	(revision 5573)
@@ -28,4 +28,76 @@
 		};
 
+	function selectNextCellCommand( backward )
+	{
+		return {
+			editorFocus : false,
+			canUndo : false,
+			modes : { wysiwyg : 1 },
+			exec : function( editor )
+			{
+				if ( editor.focusManager.hasFocus )
+				{
+					var sel = editor.getSelection(),
+							ancestor = sel.getCommonAncestor(),
+							cell;
+
+					if ( cell = ( ancestor.getAscendant( 'td', true ) || ancestor.getAscendant( 'th', true ) ) )
+					{
+						var resultRange = new CKEDITOR.dom.range( editor.document ),
+								next = CKEDITOR.tools.tryThese( function()
+								{
+									var row = cell.getParent(),
+											next = row.$.cells[ cell.$.cellIndex + ( backward ? - 1 : 1 ) ];
+
+									// Invalid any empty value.
+									next.parentNode.parentNode;
+									return next;
+								},
+								function()
+								{
+									var row = cell.getParent(),
+											table = row.getAscendant( 'table' ),
+											nextRow = table.$.rows[ row.$.rowIndex + ( backward ? - 1 : 1 ) ];
+
+									return nextRow.cells[ backward? nextRow.cells.length -1 : 0 ];
+								});
+
+						// Clone one more row at the end of table and select the first newly established cell.
+						if ( ! ( next || backward ) )
+						{
+							var table = cell.getAscendant( 'table' ).$,
+									cells = cell.getParent().$.cells;
+
+							var newRow = new CKEDITOR.dom.element( table.insertRow( -1 ), editor.document );
+
+							for ( var i = 0, count = cells.length ; i < count; i++ )
+							{
+								var newCell = newRow.append( new CKEDITOR.dom.element(
+										cells[ i ], editor.document ).clone( false, false ) );
+								!CKEDITOR.env.ie && newCell.appendBogus();
+							}
+
+							resultRange.moveToElementEditStart( newRow );
+						}
+						else if ( next )
+						{
+							next = new CKEDITOR.dom.element( next );
+							resultRange.moveToElementEditStart( next );
+							// Avoid selecting empty block makes the cursor blind.
+							if ( !( resultRange.checkStartOfBlock() && resultRange.checkEndOfBlock() ) )
+								resultRange.selectNodeContents( next );
+						}
+						else
+							return true;
+
+						resultRange.select( true );
+						return true;
+					}
+				}
+				return false;
+			}
+		};
+	}
+
 	CKEDITOR.plugins.add( 'tab',
 	{
@@ -34,5 +106,6 @@
 		init : function( editor )
 		{
-			var tabSpaces = editor.config.tabSpaces || 0,
+			var tabTools = editor.config.enableTabKeyTools !== false,
+				tabSpaces = editor.config.tabSpaces || 0,
 				tabText = '';
 
@@ -52,4 +125,14 @@
 			}
 
+			if ( tabTools )
+			{
+				editor.on( 'key', function( ev )
+				{
+					if ( ev.data.keyCode == 9 && editor.execCommand( 'selectNextCell' ) ||	// TAB
+							ev.data.keyCode == ( CKEDITOR.SHIFT + 9 ) && editor.execCommand( 'selectPreviousCell' ) )	// SHIFT+TAB
+						ev.cancel();
+				});
+			}
+
 			if ( CKEDITOR.env.webkit || CKEDITOR.env.gecko )
 			{
@@ -74,4 +157,6 @@
 			editor.addCommand( 'blur', CKEDITOR.tools.extend( blurCommand, meta ) );
 			editor.addCommand( 'blurBack', CKEDITOR.tools.extend( blurBackCommand, meta ) );
+			editor.addCommand( 'selectNextCell', selectNextCellCommand() );
+			editor.addCommand( 'selectPreviousCell', selectNextCellCommand( true ) );
 		}
 	});
@@ -260,2 +345,21 @@
  * config.tabSpaces = 4;
  */
+
+/**
+ * Allow context-sensitive tab key behaviors, including the following scenarios:
+ * <h5>When selection is anchored inside <b>table cells</b>:</h5>
+ * <ul>
+ * 		<li>If TAB is pressed, select the contents of the "next" cell. If in the last cell in the table, add a new row to it and focus its first cell.</li>
+ * 		<li>If SHIFT+TAB is pressed, select the contents of the "previous" cell. Do nothing when it's in the first cell.</li>
+ * </ul>
+ * @name CKEDITOR.config.enableTabKeyTools
+ * @type Boolean
+ * @default true
+ * @example
+ * config.enableTabKeyTools = false;
+ */
+
+CKEDITOR.config.keystrokes.push(
+	[ CKEDITOR.ALT + 38 /*Arrow Up*/, 'selectPreviousCell' ],
+	[ CKEDITOR.ALT + 40 /*Arrow Down*/, 'selectNextCell' ]
+)