<Swing Dev> RFR JDK-8226230:Test javax/swing/JInternalFrame/8020708/bug8020708.java fails on Ubuntu

[Prasanta Sadhukhan]

Hi All,

Please review a fix for an issue where this test fails in ubuntu citing 
" Close mnemonic does not work in [The CDE/Motif Look and Feel - 
com.sun.java.swing.plaf.motif.MotifLookAndFeel]"

Issue was in the test where subsequent frame with JInternalFrame were 
created almost instantaneously after the previous frame's mnemonic was 
tested. Added a delay and also make sure the frame is created in middle 
and decorations off to prevent any false clicks at wrong locations since 
the mouse needs to be moved to the menu for opening the menu which might 
overlap with ubuntu's top menubar.

Testing on ubuntu 16, 18.04 and 19.10, windows and mac is green.

diff -r 889b4191879c 
test/jdk/javax/swing/JInternalFrame/8020708/bug8020708.java
--- a/test/jdk/javax/swing/JInternalFrame/8020708/bug8020708.java Mon 
Mar 16 12:49:08 2020 +0530
+++ b/test/jdk/javax/swing/JInternalFrame/8020708/bug8020708.java Wed 
Mar 18 18:43:37 2020 +0530
@@ -57,6 +57,7 @@
          new Locale("sv"),
          new Locale("zh", "CN"),
      };
      private static final String[] LOOK_AND_FEELS = {
          "Nimbus",
@@ -87,6 +88,8 @@
              public void run() {
                  frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+               frame.setUndecorated(true);
+               frame.setLocationRelativeTo(null);
                  frame.setSize(300, 200);

                  JDesktopPane desktop = new JDesktopPane();
@@ -132,6 +135,7 @@
                  frame.dispose();
              }
          });
+       robot.delay(500);

      }
Regards
Prasanta