Program: 11070
Project: 11070
Buggy source:
public Expression resolveIdentifier(String identifier){
  IdentifierRef resultElement=resolveQueryResultElement(identifier);
  if (resultElement != null) {
    return resultElement;
  }
  AliasedQuerySource alias=resolveAlias(identifier);
  if (alias != null) {
    AliasRef result=of.createAliasRef().withName(identifier);
    if (alias.getResultType() instanceof ListType) {
      result.setResultType(((ListType)alias.getResultType()).getElementType());
    }
 else {
      result.setResultType(alias.getResultType());
    }
    return result;
  }
  LetClause let=resolveQueryLet(identifier);
  if (let != null) {
    QueryLetRef result=of.createQueryLetRef().withName(identifier);
    result.setResultType(let.getResultType());
    return result;
  }
  OperandRef operandRef=resolveOperandRef(identifier);
  if (operandRef != null) {
    return operandRef;
  }
  Element element=translatedLibrary.resolve(identifier);
  if (element == null) {
    ExpressionDefinitionInfo expressionInfo=libraryInfo.resolveExpressionReference(identifier);
    if (expressionInfo != null) {
      String saveContext=currentContext;
      currentContext=expressionInfo.getContext();
      try {
        ExpressionDef expressionDef=visitExpressionDefinition(expressionInfo.getDefinition());
        element=expressionDef;
      }
  finally {
        currentContext=saveContext;
      }
    }
    ParameterDefinitionInfo parameterInfo=libraryInfo.resolveParameterReference(identifier);
    if (parameterInfo != null) {
      ParameterDef parameterDef=visitParameterDefinition(parameterInfo.getDefinition());
      element=parameterDef;
    }
  }
  if (element instanceof ExpressionDef) {
    ExpressionRef expressionRef=of.createExpressionRef().withName(((ExpressionDef)element).getName());
    expressionRef.setResultType(getExpressionDefResultType((ExpressionDef)element));
    if (expressionRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",expressionRef.getName()));
    }
    return expressionRef;
  }
  if (element instanceof ParameterDef) {
    ParameterRef parameterRef=of.createParameterRef().withName(((ParameterDef)element).getName());
    parameterRef.setResultType(element.getResultType());
    if (parameterRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",parameterRef.getName()));
    }
    return parameterRef;
  }
  if (element instanceof ValueSetDef) {
    ValueSetRef valuesetRef=of.createValueSetRef().withName(((ValueSetDef)element).getName());
    valuesetRef.setResultType(element.getResultType());
    if (valuesetRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",valuesetRef.getName()));
    }
    return valuesetRef;
  }
  if (element instanceof CodeSystemDef) {
    CodeSystemRef codesystemRef=of.createCodeSystemRef().withName(((CodeSystemDef)element).getName());
    codesystemRef.setResultType(element.getResultType());
    if (codesystemRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",codesystemRef.getName()));
    }
    return codesystemRef;
  }
  if (element instanceof CodeDef) {
    CodeRef codeRef=of.createCodeRef().withName(((CodeDef)element).getName());
    codeRef.setResultType(element.getResultType());
    if (codeRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",codeRef.getName()));
    }
    return codeRef;
  }
  if (element instanceof ConceptDef) {
    ConceptRef conceptRef=of.createConceptRef().withName(((ConceptDef)element).getName());
    conceptRef.setResultType(element.getResultType());
    if (conceptRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",conceptRef.getName()));
    }
    return conceptRef;
  }
  if (element instanceof IncludeDef) {
    LibraryRef libraryRef=new LibraryRef();
    libraryRef.setLibraryName(((IncludeDef)element).getLocalIdentifier());
    return libraryRef;
  }
  throw new IllegalArgumentException(String.format("String_Node_Str",identifier));
}

Fixed version (ground truth):
public Expression resolveIdentifier(String identifier){
  IdentifierRef resultElement=resolveQueryResultElement(identifier);
  if (resultElement != null) {
    return resultElement;
  }
  AliasedQuerySource alias=resolveAlias(identifier);
  if (alias != null) {
    AliasRef result=of.createAliasRef().withName(identifier);
    if (alias.getResultType() instanceof ListType) {
      result.setResultType(((ListType)alias.getResultType()).getElementType());
    }
 else {
      result.setResultType(alias.getResultType());
    }
    return result;
  }
  LetClause let=resolveQueryLet(identifier);
  if (let != null) {
    QueryLetRef result=of.createQueryLetRef().withName(identifier);
    result.setResultType(let.getResultType());
    return result;
  }
  OperandRef operandRef=resolveOperandRef(identifier);
  if (operandRef != null) {
    return operandRef;
  }
  Element element=translatedLibrary.resolve(identifier);
  if (element == null) {
    ExpressionDefinitionInfo expressionInfo=libraryInfo.resolveExpressionReference(identifier);
    if (expressionInfo != null) {
      String saveContext=currentContext;
      currentContext=expressionInfo.getContext();
      try {
        ExpressionDef expressionDef=internalVisitExpressionDefinition(expressionInfo.getDefinition());
        element=expressionDef;
      }
  finally {
        currentContext=saveContext;
      }
    }
    ParameterDefinitionInfo parameterInfo=libraryInfo.resolveParameterReference(identifier);
    if (parameterInfo != null) {
      ParameterDef parameterDef=visitParameterDefinition(parameterInfo.getDefinition());
      element=parameterDef;
    }
  }
  if (element instanceof ExpressionDef) {
    ExpressionRef expressionRef=of.createExpressionRef().withName(((ExpressionDef)element).getName());
    expressionRef.setResultType(getExpressionDefResultType((ExpressionDef)element));
    if (expressionRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",expressionRef.getName()));
    }
    return expressionRef;
  }
  if (element instanceof ParameterDef) {
    ParameterRef parameterRef=of.createParameterRef().withName(((ParameterDef)element).getName());
    parameterRef.setResultType(element.getResultType());
    if (parameterRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",parameterRef.getName()));
    }
    return parameterRef;
  }
  if (element instanceof ValueSetDef) {
    ValueSetRef valuesetRef=of.createValueSetRef().withName(((ValueSetDef)element).getName());
    valuesetRef.setResultType(element.getResultType());
    if (valuesetRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",valuesetRef.getName()));
    }
    return valuesetRef;
  }
  if (element instanceof CodeSystemDef) {
    CodeSystemRef codesystemRef=of.createCodeSystemRef().withName(((CodeSystemDef)element).getName());
    codesystemRef.setResultType(element.getResultType());
    if (codesystemRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",codesystemRef.getName()));
    }
    return codesystemRef;
  }
  if (element instanceof CodeDef) {
    CodeRef codeRef=of.createCodeRef().withName(((CodeDef)element).getName());
    codeRef.setResultType(element.getResultType());
    if (codeRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",codeRef.getName()));
    }
    return codeRef;
  }
  if (element instanceof ConceptDef) {
    ConceptRef conceptRef=of.createConceptRef().withName(((ConceptDef)element).getName());
    conceptRef.setResultType(element.getResultType());
    if (conceptRef.getResultType() == null) {
      throw new IllegalArgumentException(String.format("String_Node_Str",conceptRef.getName()));
    }
    return conceptRef;
  }
  if (element instanceof IncludeDef) {
    LibraryRef libraryRef=new LibraryRef();
    libraryRef.setLibraryName(((IncludeDef)element).getLocalIdentifier());
    return libraryRef;
  }
  throw new IllegalArgumentException(String.format("String_Node_Str",identifier));
}