fixing a NPE bug in JavaProfile

solution by Alexander Weigl

Author: mattulbrich

key.core.symbolic_execution/src/main/java/de/uka/ilkd/key/symbolic_execution/strategy/SimplifyTermStrategy.java

@@ -117,7 +117,7 @@ public Strategy<Goal> create(Proof proof, StrategyProperties sp) {
          */
         @Override
         public StrategySettingsDefinition getSettingsDefinition() {
-            return JavaProfile.DEFAULT.getSettingsDefinition();
+            return JavaProfile.getDefault().getSettingsDefinition();
         }
     }
 }

key.core/src/main/java/de/uka/ilkd/key/proof/init/JavaProfile.java

@@ -48,7 +48,24 @@ public class JavaProfile extends AbstractProfile {
     public static JavaProfile defaultInstance;
     public static JavaProfile defaultInstancePermissions;
 
-    public static final StrategyFactory DEFAULT = new JavaCardDLStrategyFactory();
+    /**
+     * The default strategy factory to be used if no other strategy factory is
+     * specified.
+     *
+     * Caution: This used to be constructed at class load time, but cyclic reference between
+     * clauses made the field be read while the class was not yet fully initialized leading to
+     * null pointer exceptions. So we now use lazy initialization.
+     *
+     * (solution suggested by AW)
+     */
+    private static StrategyFactory DEFAULT;
+
+    public static StrategyFactory getDefault() {
+        if (DEFAULT == null) {
+            DEFAULT = new JavaCardDLStrategyFactory();
+        }
+        return DEFAULT;
+    }
 
     private boolean permissions = false;
 
@@ -121,7 +138,7 @@ protected ImmutableList<TermLabelConfiguration> computeTermLabelConfiguration()
     @Override
     protected ImmutableSet<StrategyFactory> getStrategyFactories() {
         ImmutableSet<StrategyFactory> set = super.getStrategyFactories();
-        set = set.add(DEFAULT);
+        set = set.add(getDefault());
         return set;
     }
 

key.ui/src/main/java/de/uka/ilkd/key/gui/StrategySelectionView.java

@@ -63,7 +63,7 @@ public final class StrategySelectionView extends JPanel implements TabPanel {
     /**
      * The always used {@link StrategyFactory}.
      */
-    private static final StrategyFactory FACTORY = JavaProfile.DEFAULT;
+    private static final StrategyFactory FACTORY = JavaProfile.getDefault();
 
     /**
      * The {@link StrategySettingsDefinition} of {@link #FACTORY} which defines the UI controls to