Double-clicking on NSOutlineView headers causes double-clicking?

Question

I have a double-click action for my NSOutlineView, everything works fine: every time I double-click on a row in a table, the correct method is called.

However, the same method is called when I double-click on the column heading (say, to change the sort order). I have never noticed this behavior before, how can I turn it off?

Answer 1

What about clickedRow validation?

[self.outlineView clickedRow]