Program: 12015
Project: 12015
Buggy source:
@Override public String getUnifiedVersionTestCaseSourceCode(String currentTestCaseSourceCode,JUnitVersion version){
  String dest=currentTestCaseSourceCode;
  ClassMeta classMeta=new ClassMetaExtractor(config).extract(currentTestCaseSourceCode);
  Configulation config=ObjectUtil.deepCopy(this.config);
  if (version == JUnitVersion.version3) {
    dest=dest.replaceAll("String_Node_Str","String_Node_Str" + config.testMethodName.basicDelimiter);
    String[] splittedArray=config.testCaseClassNameToExtend.split("String_Node_Str");
    String testCaseName=splittedArray[splittedArray.length - 1];
    dest=dest.replaceFirst(classMeta.name + "String_Node_Str",classMeta.name + "String_Node_Str" + testCaseName+ "String_Node_Str");
    config.junitVersion=JUnitVersion.version3;
    dest=addRequiredImportList(dest,config);
  }
 else   if (version == JUnitVersion.version4) {
    dest=dest.replaceAll("String_Node_Str" + config.testMethodName.basicDelimiter,"String_Node_Str");
    dest=dest.replaceFirst(classMeta.name + "String_Node_Str",classMeta.name + "String_Node_Str");
    config.junitVersion=JUnitVersion.version4;
    dest=addRequiredImportList(dest,config);
  }
  return dest;
}

Fixed version (ground truth):
@Override public String getUnifiedVersionTestCaseSourceCode(String currentTestCaseSourceCode,JUnitVersion version){
  String dest=currentTestCaseSourceCode;
  ClassMeta classMeta=new ClassMetaExtractor(config).extract(currentTestCaseSourceCode);
  Configulation config=ObjectUtil.deepCopy(this.config);
  if (version == JUnitVersion.version3) {
    dest=dest.replaceAll("String_Node_Str","String_Node_Str" + config.testMethodName.basicDelimiter);
    String[] splittedArray=config.testCaseClassNameToExtend.split("String_Node_Str");
    String testCaseName=splittedArray[splittedArray.length - 1];
    dest=dest.replaceFirst(classMeta.name + "String_Node_Str",classMeta.name + "String_Node_Str" + testCaseName+ "String_Node_Str");
    config.junitVersion=JUnitVersion.version3;
    dest=addRequiredImportList(dest,config);
  }
 else   if (version == JUnitVersion.version4) {
    dest=dest.replaceAll("String_Node_Str" + config.testMethodName.basicDelimiter,"String_Node_Str");
    String REGEXP_FOR_SUPER_CLASS="String_Node_Str";
    String REGEXP_FOR_IMPORT_TEST_CASE="String_Node_Str";
    String TEST_CASE_CLASS_WITH_PACAKGE="String_Node_Str";
    String TEST_CASE_CLASS="String_Node_Str";
    String destWithoutCRLF=dest.replaceAll("String_Node_Str","String_Node_Str").replaceAll("String_Node_Str","String_Node_Str");
    if (destWithoutCRLF.matches(REGEXP_FOR_SUPER_CLASS)) {
      Matcher matcher=Pattern.compile(REGEXP_FOR_SUPER_CLASS).matcher(destWithoutCRLF);
      if (matcher.matches()) {
        String matched=matcher.group(1);
        if (matched.trim().equals(TEST_CASE_CLASS_WITH_PACAKGE)) {
          dest=dest.replaceFirst(classMeta.name + "String_Node_Str",classMeta.name + "String_Node_Str");
        }
 else         if (matched.trim().equals(TEST_CASE_CLASS) && destWithoutCRLF.matches(REGEXP_FOR_IMPORT_TEST_CASE)) {
          dest=dest.replaceFirst(classMeta.name + "String_Node_Str",classMeta.name + "String_Node_Str").replaceAll("String_Node_Str","String_Node_Str");
        }
      }
    }
    config.junitVersion=JUnitVersion.version4;
    dest=addRequiredImportList(dest,config);
  }
  return dest;
}