diff -r 8493d5d0e9b6 -r b5a5662528fb src/Tools/JVM/java_ext_dirs
--- a/src/Tools/JVM/java_ext_dirs	Mon Mar 26 11:15:41 2012 +0200
+++ b/src/Tools/JVM/java_ext_dirs	Sat Mar 24 20:24:16 2012 +0100
@@ -17,7 +17,7 @@
 
 ## main
 
-JAVA_EXE="${THIS_JAVA:-$ISABELLE_JAVA}"
-exec "$JAVA_EXE" -classpath "$(jvmpath "$ISABELLE_HOME/src/Tools/JVM/java_ext_dirs.jar")" \
+exec "$ISABELLE_JDK_HOME/bin/java" \
+  -classpath "$(jvmpath "$ISABELLE_HOME/src/Tools/JVM/java_ext_dirs.jar")" \
   isabelle.Java_Ext_Dirs "$(jvmpath "$ISABELLE_HOME/lib/classes/ext")"