Are there any valid circumstances where foo=foo makes sense?

Question

Cleaning a handful of warnings on a C# project I have inherited, I found this code snippet:

private bool _WriteValue(object FieldValue,..,..)
  ...
  if(MultipFactor!=1)
     FieldValue=((double)FieldValue)*MultipFactor;
  else
    FieldValue=FieldValue;

I've obviously burninated the else block without thinking too much, just wondering why the previous programmer has left that part.

• Was it just too lazy to delete it?
• Was it a courtesy for some future programmers to save some typing in case of specific changes?
• Is it hiding something dangerous?

In your opinion, are there any valid circumstances where foo=foo makes sense?

---

Some more details on the _WriteValue method:

The _WriteValue method is wrapped into different overloaded WriteValue methods that pass to the object FieldValue parameter, values of the following types: int, long, string and Datetime.

Answer 1

If FieldValue is a property, the set operator could trigger some code, so a self-assignment could make sense in such a case?!

An example would be:

public string FieldValue
{
    get
    {
        return _fieldValue;
    }
    set
    {
        _fieldValue = value;
        Trace.WriteLine( string.Format("Received value '{0}'.", value ) );
    }
}

(My answer was given before the poster added the information that FieldValue actually is a method parameter, not a property as I assumed first)