HashSet <T> .RemoveWhere () and GetHashCode ()

Aloha

Here is a simple class that overrides GetHashCode:

class OverridesGetHashCode
{
    public string Text { get; set; }

    public override int GetHashCode()
    {
        return (Text != null ? Text.GetHashCode() : 0);
    }
    // overriding Equals() doesn't change anything, so I'll leave it out for brevity
}

When I instantiate this class, add it to the HashSet and then change its Text property, for example:

var hashset = new HashSet<OverridesGetHashCode>();
var oghc = new OverridesGetHashCode { Text = "1" };
hashset.Add(oghc);
oghc.Text = "2";

then this will not work:

var removedCount = hashset.RemoveWhere(c => ReferenceEquals(c, oghc));
// fails, nothing is removed
Assert.IsTrue(removedCount == 1);

and does not do this:

// this line works, i.e. it does find a single item matching the predicate
var existing = hashset.Single(c => ReferenceEquals(c, oghc));
// but this fails; nothing is removed again
var removed = hashset.Remove(existing);
Assert.IsTrue(removed); 

I assume that the hash that it uses internally is generated when the element is inserted, and if true, it is clear that hashset.Contains (oghc) is not working. I also assume that it looks at the element by its hash code, and if it finds a match, only then it checks the predicate, and that is probably why the first test fails (again, I just guess here). But why does the last test fail, I just got this object from hashset? Am I missing something, is this the wrong way to remove something from a HashSet?

, , .

. , Equals():

protected bool Equals(OverridesGetHashCode other)
    {
        return string.Equals(Text, other.Text);
    }

public override bool Equals(object obj)
    {
        if (ReferenceEquals(null, obj)) return false;
        if (ReferenceEquals(this, obj)) return true;
        if (obj.GetType() != this.GetType()) return false;
        return Equals((OverridesGetHashCode) obj);
    }