Program: 29675
Project: 29675
Buggy source:
public String processRefToExternalDefinition(String $ref,RefFormat refFormat){
  final Model model=cache.loadRef($ref,refFormat,Model.class);
  String newRef;
  Map<String,Model> definitions=swagger.getDefinitions();
  if (definitions == null) {
    definitions=new HashMap<>();
  }
  final String possiblyConflictingDefinitionName=computeDefinitionName($ref);
  final Model existingModel=definitions.get(possiblyConflictingDefinitionName);
  if (existingModel != null) {
    LOGGER.debug("String_Node_Str" + existingModel + "String_Node_Str");
  }
  newRef=possiblyConflictingDefinitionName;
  cache.putRenamedRef($ref,newRef);
  String file=$ref.split("String_Node_Str")[0];
  if (model instanceof RefModel) {
    RefModel refModel=(RefModel)model;
    if (isAnExternalRefFormat(refModel.getRefFormat())) {
      refModel.set$ref(processRefToExternalDefinition(refModel.get$ref(),refModel.getRefFormat()));
    }
 else {
      processRefToExternalDefinition(file + refModel.get$ref(),RefFormat.RELATIVE);
    }
  }
  Map<String,Property> subProps=model.getProperties();
  if (subProps != null) {
    for (    Map.Entry<String,Property> prop : subProps.entrySet()) {
      if (prop.getValue() instanceof RefProperty) {
        RefProperty subRef=(RefProperty)prop.getValue();
        if (isAnExternalRefFormat(subRef.getRefFormat())) {
          subRef.set$ref(processRefToExternalDefinition(subRef.get$ref(),subRef.getRefFormat()));
        }
 else {
          processRefToExternalDefinition(file + subRef.get$ref(),RefFormat.RELATIVE);
        }
      }
 else       if (prop.getValue() instanceof ArrayProperty) {
        ArrayProperty arrayProp=(ArrayProperty)prop.getValue();
        if (arrayProp.getItems() instanceof RefProperty) {
          RefProperty subRef=(RefProperty)arrayProp.getItems();
          if (isAnExternalRefFormat(subRef.getRefFormat())) {
            subRef.set$ref(processRefToExternalDefinition(subRef.get$ref(),subRef.getRefFormat()));
          }
 else {
            processRefToExternalDefinition(file + subRef.get$ref(),RefFormat.RELATIVE);
          }
        }
      }
 else       if (prop.getValue() instanceof MapProperty) {
        MapProperty mapProp=(MapProperty)prop.getValue();
        if (mapProp.getAdditionalProperties() instanceof RefProperty) {
          RefProperty subRef=(RefProperty)mapProp.getAdditionalProperties();
          if (isAnExternalRefFormat(subRef.getRefFormat())) {
            subRef.set$ref(processRefToExternalDefinition(subRef.get$ref(),subRef.getRefFormat()));
          }
 else {
            processRefToExternalDefinition(file + subRef.get$ref(),RefFormat.RELATIVE);
          }
        }
      }
    }
  }
  if (model instanceof ArrayModel && ((ArrayModel)model).getItems() instanceof RefProperty) {
    RefProperty subRef=(RefProperty)((ArrayModel)model).getItems();
    if (isAnExternalRefFormat(subRef.getRefFormat())) {
      subRef.set$ref(processRefToExternalDefinition(subRef.get$ref(),subRef.getRefFormat()));
    }
 else {
      processRefToExternalDefinition(file + subRef.get$ref(),RefFormat.RELATIVE);
    }
  }
  if (existingModel == null) {
    swagger.addDefinition(newRef,model);
  }
  return newRef;
}

Fixed version (ground truth):
public String processRefToExternalDefinition(String $ref,RefFormat refFormat){
  final Model model=cache.loadRef($ref,refFormat,Model.class);
  String newRef;
  Map<String,Model> definitions=swagger.getDefinitions();
  if (definitions == null) {
    definitions=new HashMap<>();
  }
  final String possiblyConflictingDefinitionName=computeDefinitionName($ref);
  final Model existingModel=definitions.get(possiblyConflictingDefinitionName);
  if (existingModel != null) {
    LOGGER.debug("String_Node_Str" + existingModel + "String_Node_Str");
  }
  newRef=possiblyConflictingDefinitionName;
  cache.putRenamedRef($ref,newRef);
  if (existingModel == null) {
    swagger.addDefinition(newRef,model);
    String file=$ref.split("String_Node_Str")[0];
    if (model instanceof RefModel) {
      RefModel refModel=(RefModel)model;
      if (isAnExternalRefFormat(refModel.getRefFormat())) {
        refModel.set$ref(processRefToExternalDefinition(refModel.get$ref(),refModel.getRefFormat()));
      }
 else {
        processRefToExternalDefinition(file + refModel.get$ref(),RefFormat.RELATIVE);
      }
    }
    Map<String,Property> subProps=model.getProperties();
    if (subProps != null) {
      for (      Map.Entry<String,Property> prop : subProps.entrySet()) {
        if (prop.getValue() instanceof RefProperty) {
          processRefProperty((RefProperty)prop.getValue(),file);
        }
 else         if (prop.getValue() instanceof ArrayProperty) {
          ArrayProperty arrayProp=(ArrayProperty)prop.getValue();
          if (arrayProp.getItems() instanceof RefProperty) {
            processRefProperty((RefProperty)arrayProp.getItems(),file);
          }
        }
 else         if (prop.getValue() instanceof MapProperty) {
          MapProperty mapProp=(MapProperty)prop.getValue();
          if (mapProp.getAdditionalProperties() instanceof RefProperty) {
            processRefProperty((RefProperty)mapProp.getAdditionalProperties(),file);
          }
 else           if (mapProp.getAdditionalProperties() instanceof ArrayProperty && ((ArrayProperty)mapProp.getAdditionalProperties()).getItems() instanceof RefProperty) {
            processRefProperty((RefProperty)((ArrayProperty)mapProp.getAdditionalProperties()).getItems(),file);
          }
        }
      }
    }
    if (model instanceof ArrayModel && ((ArrayModel)model).getItems() instanceof RefProperty) {
      processRefProperty((RefProperty)((ArrayModel)model).getItems(),file);
    }
  }
  return newRef;
}