Bug 44861 [CellEditors] DialogCellEditor does not handle focusLost()
Make sure you have org.eclipse.ui.examples.propertysheet_2.1.0 and open any *.usr file. Select "Richard" from the outline view and select "eyecolor" from the properties view (notice the ... button). Now open the search dialog and notice the ... button is still there. If you select other text or combo properties, notice the editor has been deactivated.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/DialogCellEditor.java
return buttonFocusListener;
	}
	/* (non-Javadoc)
     * Method declared on CellEditor.
     */
    protected void doSetValue(Object value) {
        this.value = value;
        updateContents(value);
    }
    /**
     * Returns the default label widget created by <code>createContents</code>.
     *
     * @return the default label widget
     */
    protected Label getDefaultLabel() {
        return defaultLabel;
    }
    /**
     * Opens a dialog box under the given parent control and returns the
     * dialog's value when it closes, or <code>null</code> if the dialog
     * was cancelled or no selection was made in the dialog.
     * <p>
     * This framework method must be implemented by concrete subclasses.
     * It is called when the user has pressed the button and the dialog
     * box must pop up.
     * </p>
     *
     * @param cellEditorWindow the parent control cell editor's window
     *   so that a subclass can adjust the dialog box accordingly