git: openjdk/jtharness: 7903015: TestTreePanel::initGUI adds preferences observer that could throw NPE if workDir is null

[Dmitry Bessonov]

Changeset: 3e3672d2
Author:    Dmitry Bessonov <dmitry.bessonov at oracle.com>
Date:      2021-08-16 17:33:05 +0000
URL:       https://git.openjdk.java.net/jtharness/commit/3e3672d2eb3f85b7f9845b1807169e5cc4392294

7903015: TestTreePanel::initGUI adds preferences observer that could throw NPE if workDir is null

! src/com/sun/javatest/exec/TestTreePanel.java