7077826: Unset and empty DISPLAY variable is handled differently by JDK

Reviewed-by: azvegint, ant

src/share/classes/java/awt/GraphicsEnvironment.java

@@ -28,6 +28,7 @@ package java.awt;
 
 import java.awt.image.BufferedImage;
 import java.security.AccessController;
+import java.security.PrivilegedAction;
 import java.util.Locale;
 
 import sun.font.FontManager;
@@ -160,9 +161,7 @@ public abstract class GraphicsEnvironment {
      */
     private static boolean getHeadlessProperty() {
         if (headless == null) {
-            java.security.AccessController.doPrivileged(
-            new java.security.PrivilegedAction<Object>() {
-                public Object run() {
+            AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
                 String nm = System.getProperty("java.awt.headless");
 
                 if (nm == null) {
@@ -176,27 +175,24 @@ public abstract class GraphicsEnvironment {
                         {
                             headless = defaultHeadless = Boolean.TRUE;
                         } else {
+                            final String display = System.getenv("DISPLAY");
                             headless = defaultHeadless =
-                                    Boolean.valueOf(("Linux".equals(osName) ||
+                                ("Linux".equals(osName) ||
                                  "SunOS".equals(osName) ||
                                  "FreeBSD".equals(osName) ||
                                  "NetBSD".equals(osName) ||
                                  "OpenBSD".equals(osName) ||
                                  "AIX".equals(osName)) &&
-                                                     (System.getenv("DISPLAY") == null));
+                                 (display == null || display.trim().isEmpty());
                         }
                     }
-                    } else if (nm.equals("true")) {
-                        headless = Boolean.TRUE;
                 } else {
-                        headless = Boolean.FALSE;
+                    headless = Boolean.valueOf(nm);
                 }
                 return null;
+            });
         }
-                }
-            );
-        }
-        return headless.booleanValue();
+        return headless;
     }
 
     /**

test/java/awt/GraphicsEnvironment/TestDetectHeadless/TestDetectHeadless.sh

@@ -28,7 +28,7 @@
 #
 
 # @test
-# @bug 8058930
+# @bug 8058930 7077826
 # @summary java.awt.GraphicsEnvironment.getHeadlessProperty() does not work for AIX
 #
 # @build TestDetectHeadless
@@ -36,11 +36,21 @@
 
 OS=`uname -s`
 case "$OS" in
-    Windows* | CYGWIN* )
+    Windows* | CYGWIN* | Darwin)
         echo "Passed"; exit 0 ;;
     * ) unset DISPLAY ;;
 esac
 
+${TESTJAVA}/bin/java ${TESTVMOPTS} \
+    -cp ${TESTCLASSES} TestDetectHeadless
+
+if [ $? -ne 0 ]; then
+	exit 1;
+fi
+
+DISPLAY=
+export DISPLAY
+
 ${TESTJAVA}/bin/java ${TESTVMOPTS} \
     -cp ${TESTCLASSES} TestDetectHeadless
 

test/java/awt/Toolkit/BadDisplayTest/BadDisplayTest.sh

-# Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -21,23 +21,15 @@
 
 ${TESTJAVA}/bin/javac -cp ${TESTSRC} -d . ${TESTSRC}/BadDisplayTest.java
 
-
-DISPLAY=
-export DISPLAY
-
 OS=`uname -s`
 case "$OS" in
-  SunOS )
-    ${TESTJAVA}/bin/java BadDisplayTest
-    ;;
-  Linux )
-    ${TESTJAVA}/bin/java BadDisplayTest
-     ;;
-  * )
-    echo "Unsupported System: ${OS}"
-    exit 0;
-    ;;
+    Windows* | CYGWIN* | Darwin)
+        echo "Passed"; exit 0 ;;
 esac
 
-exit $?
+DISPLAY=SomeBadDisplay
+export DISPLAY
+
+${TESTJAVA}/bin/java ${TESTVMOPTS} BadDisplayTest
 
+exit $?