Fix NullPointerException

Author: rcosta358

liquidjava-verifier/src/main/java/liquidjava/processor/refinement_checker/MethodsFirstChecker.java

@@ -96,16 +96,24 @@ public <T> void visitCtInterface(CtInterface<T> intrface) {
     @Override
     public <T> void visitCtConstructor(CtConstructor<T> c) {
         context.enterContext();
-        getRefinementFromAnnotation(c);
-        mfc.getConstructorRefinements(c);
-        super.visitCtConstructor(c);
+        try {
+            getRefinementFromAnnotation(c);
+            mfc.getConstructorRefinements(c);
+            super.visitCtConstructor(c);
+        } catch (LJError e) {
+            diagnostics.add(e);
+        }
         context.exitContext();
     }
 
     public <R> void visitCtMethod(CtMethod<R> method) {
         context.enterContext();
-        mfc.getMethodRefinements(method);
-        super.visitCtMethod(method);
+        try {
+            mfc.getMethodRefinements(method);
+            super.visitCtMethod(method);
+        } catch (LJError e) {
+            diagnostics.add(e);
+        }
         context.exitContext();
     }
 }

liquidjava-verifier/src/main/java/liquidjava/processor/refinement_checker/general_checkers/MethodsFunctionsChecker.java

@@ -181,6 +181,8 @@ public <R> void getReturnRefinements(CtReturn<R> ret) throws LJError {
             if (method.getParent() instanceof CtClass) {
                 RefinedFunction fi = rtc.getContext().getFunction(method.getSimpleName(),
                         ((CtClass<?>) method.getParent()).getQualifiedName(), method.getParameters().size());
+                if (fi == null)
+                    return;
 
                 List<Variable> lv = fi.getArguments();
                 for (Variable v : lv) {