Program: 9144
Project: 9144
Buggy source:
/** 
 * If the source version warrants, add a -bootclasspath entry to the list of arguments to add.  This will fail and return an error String if the  required library is not found.
 * @param sourceVersion the String (if any) describing the -source option(expecting one of [null, "1.3", "1.4", "1.5"].
 * @param compilerName the String name of the target compiler
 * @param toAdd the ArrayList to add -bootclasspath to
 * @return the String describing any errors, or null if no errors
 */
private static String updateBootclasspathForSourceVersion(String sourceVersion,String compilerName,ArrayList toAdd){
  if (null == sourceVersion) {
    return null;
  }
  if (3 != sourceVersion.length()) {
    throw new IllegalArgumentException("String_Node_Str" + sourceVersion);
  }
  if (null == toAdd) {
    throw new IllegalArgumentException("String_Node_Str");
  }
  int version=sourceVersion.charAt(2) - '0';
switch (version) {
case (3):
    if (LangUtil.supportsJava("String_Node_Str")) {
      if (!FileUtil.canReadFile(Globals.J2SE13_RTJAR)) {
        return "String_Node_Str";
      }
      toAdd.add("String_Node_Str");
      toAdd.add(Globals.J2SE13_RTJAR.getAbsolutePath());
    }
  break;
case (4):
if (!LangUtil.supportsJava("String_Node_Str")) {
  if (ReflectionFactory.ECLIPSE.equals(compilerName)) {
    return "String_Node_Str";
  }
  if (!FileUtil.canReadFile(Globals.J2SE14_RTJAR)) {
    return "String_Node_Str";
  }
  toAdd.add("String_Node_Str");
  toAdd.add(Globals.J2SE14_RTJAR.getAbsolutePath());
}
break;
case (5):
return "String_Node_Str";
case (0):
break;
default :
throw new Error("String_Node_Str" + version);
}
return null;
}

Fixed version (ground truth):
/** 
 * If the source version warrants, add a -bootclasspath entry to the list of arguments to add.  This will fail and return an error String if the  required library is not found.
 * @param sourceVersion the String (if any) describing the -source option(expecting one of [null, "1.3", "1.4", "1.5"].
 * @param compilerName the String name of the target compiler
 * @param toAdd the ArrayList to add -bootclasspath to
 * @return the String describing any errors, or null if no errors
 */
private static String updateBootclasspathForSourceVersion(String sourceVersion,String compilerName,ArrayList toAdd){
  if (null == sourceVersion) {
    return null;
  }
  if (3 != sourceVersion.length()) {
    throw new IllegalArgumentException("String_Node_Str" + sourceVersion);
  }
  if (null == toAdd) {
    throw new IllegalArgumentException("String_Node_Str");
  }
  int version=sourceVersion.charAt(2) - '0';
switch (version) {
case (3):
    if (Globals.supportsJava("String_Node_Str")) {
      if (!FileUtil.canReadFile(Globals.J2SE13_RTJAR)) {
        return "String_Node_Str";
      }
      toAdd.add("String_Node_Str");
      toAdd.add(Globals.J2SE13_RTJAR.getAbsolutePath());
    }
  break;
case (4):
if (!Globals.supportsJava("String_Node_Str")) {
  if (ReflectionFactory.ECLIPSE.equals(compilerName)) {
    return "String_Node_Str";
  }
  if (!FileUtil.canReadFile(Globals.J2SE14_RTJAR)) {
    return "String_Node_Str";
  }
  toAdd.add("String_Node_Str");
  toAdd.add(Globals.J2SE14_RTJAR.getAbsolutePath());
}
break;
case (5):
return "String_Node_Str";
case (0):
break;
default :
throw new Error("String_Node_Str" + version);
}
return null;
}