Bug 161425 [Viewers] TableTreeViewer => EditingSupport broken
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TableTreeViewer.java
this.cellEditor = null;
				Item t = this.tableItem;
				
				if (t != null && !t.isDisposed()) {
					saveEditorValue(c, t);
				}
				setEditor(null, null, 0);
				c.removeListener(cellEditorListener);
				Control control = c.getControl();
				if (control != null) {
					if (mouseListener != null) {
						control.removeMouseListener(mouseListener);
					}
					if (focusListener != null) {
						control.removeFocusListener(focusListener);
					}
				}
				c.deactivate();
			}
		}
		/**
		 * Cancels the active cell editor, without saving the value back to the
		 * domain model.
		 */
		public void cancelEditing() {
			if (cellEditor != null) {
				setEditor(null, null, 0);
				cellEditor.removeListener(cellEditorListener);
				CellEditor oldEditor = cellEditor;