Program: 13869
Project: 13869
Buggy source:
private static Member createPropertyMemberIfValidProperty(Clazz clazz,TypeElement interfaceElement,Configuration configuration,ExecutableElement methodElement,PropertyKind kind,DiagnosticMessageConsumer errorConsumer) throws Exception {
  TypeMirror propertyType;
  List<? extends VariableElement> setterParams=methodElement.getParameters();
  if (kind == PropertyKind.GETTER) {
    if (setterParams.size() != 0) {
      if (!configuration.isMalformedPropertiesIgnored())       errorConsumer.message(methodElement,Kind.ERROR,String.format(ProcessorMessages.MalFormedGetter,methodElement.toString()));
      return null;
    }
    TypeMirror returnType=methodElement.getReturnType();
    propertyType=returnType;
    return new Member(clazz,new Type(clazz,propertyType),syntesisePropertyMemberName(methodElement));
  }
 else   if (kind == PropertyKind.SETTER) {
    if (setterParams.size() != 1) {
      if (!configuration.isMalformedPropertiesIgnored())       errorConsumer.message(methodElement,Kind.ERROR,String.format(ProcessorMessages.MalFormedSetter,methodElement.toString()));
      return null;
    }
    TypeMirror returnType=methodElement.getReturnType();
    String returnTypeName=returnType.toString();
    if (!returnTypeName.equals("String_Node_Str") && !returnTypeName.equals(interfaceElement.toString()) && !returnTypeName.equals(clazz.getQualifiedName())) {
      if (!configuration.isMalformedPropertiesIgnored())       errorConsumer.message(methodElement,Kind.ERROR,String.format(ProcessorMessages.MalFormedSetter,methodElement.toString()));
      return null;
    }
    propertyType=setterParams.get(0).asType();
  }
 else {
    return null;
  }
  return new Member(clazz,new Type(clazz,propertyType),syntesisePropertyMemberName(methodElement));
}

Fixed version (ground truth):
private static Member createPropertyMemberIfValidProperty(Clazz clazz,TypeElement interfaceElement,Configuration configuration,ExecutableElement methodElement,PropertyKind kind,DiagnosticMessageConsumer errorConsumer) throws Exception {
  TypeMirror propertyType;
  List<? extends VariableElement> setterParams=methodElement.getParameters();
  if (kind == PropertyKind.GETTER) {
    if (setterParams.size() != 0) {
      if (!configuration.isMalformedPropertiesIgnored())       errorConsumer.message(methodElement,Kind.ERROR,String.format(ProcessorMessages.MalFormedGetter,methodElement.toString()));
      return null;
    }
    TypeMirror returnType=methodElement.getReturnType();
    propertyType=returnType;
    return new Member(clazz,new Type(clazz,propertyType),syntesisePropertyMemberName(configuration.getGetterPrefixes(),methodElement));
  }
 else   if (kind == PropertyKind.SETTER) {
    if (setterParams.size() != 1) {
      if (!configuration.isMalformedPropertiesIgnored())       errorConsumer.message(methodElement,Kind.ERROR,String.format(ProcessorMessages.MalFormedSetter,methodElement.toString()));
      return null;
    }
    TypeMirror returnType=methodElement.getReturnType();
    String returnTypeName=returnType.toString();
    if (!returnTypeName.equals("String_Node_Str") && !returnTypeName.equals(interfaceElement.toString()) && !returnTypeName.equals(clazz.getQualifiedName())) {
      if (!configuration.isMalformedPropertiesIgnored())       errorConsumer.message(methodElement,Kind.ERROR,String.format(ProcessorMessages.MalFormedSetter,methodElement.toString()));
      return null;
    }
    propertyType=setterParams.get(0).asType();
    return new Member(clazz,new Type(clazz,propertyType),syntesisePropertyMemberName(configuration.getSetterPrefixes(),methodElement));
  }
 else {
    return null;
  }
}