I'm using MacVim with the NERD tree plugin.
When I close MacVim I get a model window saying
There are several documents with unsaved changes. and asking me if I want to save those changes.
That's fine but something the only unsaved document is the NERD tree window. In this case the message I get is like
There are several documents with unsaved changes. Do you want to save the changes you made in the document "NERD_tree_3"?.
Is there a way to set MacVim so that it ignores unsaved NERD tree windows when closing?