Finding the parent tree of a GtkTreeItem

[Chris Phelps <chicane reninet com>]

I need to find the parent tree of a GtkTreeItem that does not have a
subtree. I know this must be possible, because
gtk_tree_item_set_subtree() sets GtkTreeItem->subtree->root_tree to the
parent tree of the original GtkTreeItem. I could hack this by setting a
subtree for the GtkTreeItem and then getting the parent tree that way,
but that seems a little crude, and I prefer not to code quite that badly
if at all possible. If anyone knows how to find the GtkTree parent of a
GtkTreeItem without a lot of hackish code, i would appreciate being
informed.

Later,
Chicane