bundles/org.eclipse.orion.client.editor/web/orion/editor/undoStack.js
function() {
			this._commitUndo();
			var change, result = false;
			this._ignoreUndo = true;
			do {
				if (this.index <= 0) {
					break;
				}
				change = this.stack[--this.index];
			} while (!(result = change.undo(this.view, true)));
			this._ignoreUndo = false;
			return result;
		}
function() {
			this._commitUndo();
			var change, result = false;
			this._ignoreUndo = true;
			do {
				if (this.index <= 0) {
					break;
				}
				change = this.stack[--this.index];
			} while (!(result = change.undo(this.view, true)));
			this._ignoreUndo = false;
			return result;
		}
function ( ) { this . _commitUndo ( ) ; var change , result = false ; this . _ignoreUndo = true ; do { if ( this . index <= 0 ) { break ; } change = this . stack [ -- this . index ] ; } while ( ! ( result = change . undo ( this . view , true ) ) ) ; this . _ignoreUndo = false ; return result ; }
Undo the last change in the stack.

@return {Boolean} returns true if a change was un-done.

@see orion.editor.UndoStack#redo
@see orion.editor.UndoStack#canUndo
Undo the last change in the stack .