Program: 157099
Project: 157099
Buggy source:
public List addTabCompletionOptions(ICommandSender commandSender,String[] args){
switch (args.length) {
case 1:
{
      return getListOfStringsMatchingLastWord(args,new String[]{"String_Node_Str","String_Node_Str","String_Node_Str"});
    }
case 2:
{
    if (args[0].equalsIgnoreCase("String_Node_Str")) {
      return getListOfStringsMatchingLastWord(args,new String[]{"String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str","String_Node_Str"});
    }
 else     if (args[0].equalsIgnoreCase("String_Node_Str")) {
      return getListOfStringsMatchingLastWord(args,new String[]{"String_Node_Str","String_Node_Str"});
    }
 else     if (args[0].equalsIgnoreCase("String_Node_Str")) {
      return getListOfStringsMatchingLastWord(args,new String[]{"String_Node_Str","String_Node_Str","String_Node_Str"});
    }
  }
case 3:
{
  if (args[0].equalsIgnoreCase("String_Node_Str")) {
    if (args[1].equalsIgnoreCase("String_Node_Str")) {
      return getListOfStringsMatchingLastWord(args,new String[]{"String_Node_Str","String_Node_Str"});
    }
  }
}
case 4:
{
if (args[0].equalsIgnoreCase("String_Node_Str")) {
  if (args[1].equalsIgnoreCase("String_Node_Str")) {
    if (args[2].equalsIgnoreCase("String_Node_Str") || args[2].equalsIgnoreCase("String_Node_Str")) {
      return getListOfStringsMatchingLastWord(args,new String[]{"String_Node_Str","String_Node_Str"});
    }
  }
}
}
default :
{
return null;
}
}
}

Fixed version (ground truth):
public List addTabCompletionOptions(ICommandSender commandSender,String[] args){
switch (args.length) {
case 1:
{
      return getListOfStringsMatchingLastWord(args,new String[]{getLocalizedString(COMMAND_OVERLAY),getLocalizedString(COMMAND_PARTICLES),getLocalizedString(COMMAND_SOUNDS)});
    }
case 2:
{
    if (args[0].equalsIgnoreCase(getLocalizedString(COMMAND_OVERLAY))) {
      return getListOfStringsMatchingLastWord(args,new String[]{getLocalizedString(COMMAND_ON),getLocalizedString(COMMAND_OFF),getLocalizedString(COMMAND_POSITION),getLocalizedString(COMMAND_SCALE),getLocalizedString(COMMAND_OPACITY)});
    }
 else     if (args[0].equalsIgnoreCase(getLocalizedString(COMMAND_PARTICLES))) {
      return getListOfStringsMatchingLastWord(args,new String[]{getLocalizedString(COMMAND_ON),getLocalizedString(COMMAND_OFF)});
    }
 else     if (args[0].equalsIgnoreCase(getLocalizedString(COMMAND_SOUNDS))) {
      return getListOfStringsMatchingLastWord(args,new String[]{getLocalizedString(COMMAND_ALL),getLocalizedString(COMMAND_SELF),getLocalizedString(COMMAND_OFF)});
    }
  }
case 3:
{
  if (args[0].equalsIgnoreCase(getLocalizedString(COMMAND_OVERLAY))) {
    if (args[1].equalsIgnoreCase(getLocalizedString(COMMAND_POSITION))) {
      return getListOfStringsMatchingLastWord(args,new String[]{getLocalizedString(COMMAND_TOP),getLocalizedString(COMMAND_BOTTOM)});
    }
  }
}
case 4:
{
if (args[0].equalsIgnoreCase(getLocalizedString(COMMAND_OVERLAY))) {
  if (args[1].equalsIgnoreCase(getLocalizedString(COMMAND_POSITION))) {
    if (args[2].equalsIgnoreCase(getLocalizedString(COMMAND_TOP)) || args[2].equalsIgnoreCase(getLocalizedString(COMMAND_BOTTOM))) {
      return getListOfStringsMatchingLastWord(args,new String[]{getLocalizedString(COMMAND_LEFT),getLocalizedString(COMMAND_RIGHT)});
    }
  }
}
}
default :
{
return null;
}
}
}