Avoid NPE seen in real life
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/objectteams/otdt/internal/core/compiler/mappings/CallinImplementorDyn.java b/org.eclipse.jdt.core/compiler/org/eclipse/objectteams/otdt/internal/core/compiler/mappings/CallinImplementorDyn.java
index 0949047..6a9e2cd 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/objectteams/otdt/internal/core/compiler/mappings/CallinImplementorDyn.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/objectteams/otdt/internal/core/compiler/mappings/CallinImplementorDyn.java
@@ -937,7 +937,8 @@
roleSideArgument = gen.resolvedCastExpression(roleSideArgument, roleSideParameter, CastExpression.RAW);
TypeBinding roleSideLeaf = roleSideParameter.leafComponentType();
TypeBinding baseSideLeaf = baseSideParameter.leafComponentType();
- if ( roleSideLeaf.isRole()
+ if ( roleSideLeaf.isRole()
+ && ((ReferenceBinding)roleSideLeaf).baseclass() != null
&& ((ReferenceBinding)roleSideLeaf).baseclass().isCompatibleWith(baseSideLeaf))
roleSideArgument = new PotentialLowerExpression(roleSideArgument, baseSideParameter, gen.thisReference());
repackingStats.add(gen.assignment(gen.arrayReference(gen.singleNameReference(ARGUMENTS), // arguments[p] = baseCallArguments[i];
