fix for Bugzilla Bug 51322

 	Introduce Unknown Type to class causes Null pointer exception

org.aspectj.ajdt.core/src/org/aspectj/ajdt/internal/compiler/ast/InterTypeMethodDeclaration.java

@@ -28,6 +28,7 @@ import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
 import org.eclipse.jdt.internal.compiler.flow.InitializationFlowContext;
 import org.eclipse.jdt.internal.compiler.lookup.*;
 import org.eclipse.jdt.internal.compiler.parser.Parser;
+import org.eclipse.jdt.internal.compiler.problem.AbortCompilation;
 
 /**
  * An inter-type method declaration.
@@ -101,6 +102,11 @@ public class InterTypeMethodDeclaration extends InterTypeDeclaration {
 		if (ignoreFurtherInvestigation) return null;
 		
 		binding = classScope.referenceContext.binding.resolveTypesFor(binding);
+		if (binding == null) {
+			// if binding is null, we failed to find a type used in the method params, this error
+			// has already been reported. 
+			throw new AbortCompilation();
+		}
 		ResolvedMember sig = new ResolvedMember(Member.METHOD, EclipseFactory.fromBinding(onTypeBinding),
 			declaredModifiers, EclipseFactory.fromBinding(binding.returnType), new String(declaredSelector),
 			EclipseFactory.fromBindings(binding.parameters),

tests/ajcTests.xml

@@ -7303,4 +7303,11 @@
             <message kind="error" line="6"/> 
         </compile>
     </ajc-test>
+    
+    <ajc-test dir="bugs"  pr="51322"
+    	title="Introduce Unknown Type to class causes Null pointer exception"  >
+        <compile files="Pr51322.java"> 
+        	<message kind="error" line="5"/>
+        </compile>
+    </ajc-test>
 </suite>

tests/bugs/Pr51322.java

@@ -0,0 +1,6 @@
+class A {}
+public abstract aspect Pr51322
+{
+  public void A.aMethod(Object x) {}
+  public void A.someMethod(WCharType a) { }
+}