Program: 29679
Project: 29679
Buggy source:
public String processRefToExternalDefinition(String $ref,RefFormat refFormat){
  System.out.println("String_Node_Str" + $ref);
  final Model model=cache.loadRef($ref,refFormat,Model.class);
  if (model == null) {
    System.out.println("String_Node_Str" + $ref);
    ;
  }
  String newRef;
  Map<String,Model> definitions=swagger.getDefinitions();
  if (definitions == null) {
    definitions=new HashMap<>();
  }
  final String possiblyConflictingDefinitionName=computeDefinitionName($ref);
  final Model existingModel=definitions.get(possiblyConflictingDefinitionName);
  if (existingModel != null) {
    final String previouslyRenamedRef=cache.getRenamedRef($ref);
    if (previouslyRenamedRef != null) {
      newRef=previouslyRenamedRef;
    }
 else {
      String deconflictedName=deconflictName(possiblyConflictingDefinitionName,definitions);
      cache.putRenamedRef($ref,deconflictedName);
      newRef=deconflictedName;
      swagger.addDefinition(deconflictedName,model);
    }
  }
 else {
    newRef=possiblyConflictingDefinitionName;
    cache.putRenamedRef($ref,newRef);
    Map<String,Property> subProps=model.getProperties();
    if (subProps != null) {
      for (      Map.Entry<String,Property> prop : subProps.entrySet()) {
        if (prop.getValue() instanceof RefProperty) {
          RefProperty subRef=(RefProperty)prop.getValue();
          System.out.println(subRef.get$ref() + "String_Node_Str" + subRef.getRefFormat());
          if (isAnExternalRefFormat(subRef.getRefFormat()))           subRef.set$ref(processRefToExternalDefinition(subRef.get$ref(),subRef.getRefFormat()));
        }
      }
    }
    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($ref);
  final Model existingModel=definitions.get(possiblyConflictingDefinitionName);
  if (existingModel != null) {
    final String previouslyRenamedRef=cache.getRenamedRef($ref);
    if (previouslyRenamedRef != null) {
      newRef=previouslyRenamedRef;
    }
 else {
      String deconflictedName=deconflictName(possiblyConflictingDefinitionName,definitions);
      cache.putRenamedRef($ref,deconflictedName);
      newRef=deconflictedName;
      swagger.addDefinition(deconflictedName,model);
    }
  }
 else {
    newRef=possiblyConflictingDefinitionName;
    cache.putRenamedRef($ref,newRef);
    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()));
        }
      }
    }
    swagger.addDefinition(newRef,model);
  }
  return newRef;
}