Please describe the problem:
If you start editing in a treeview cell, but do not commit the edit by pressing Enter, then the edit-in-progress is lost if the treeview window is de-focused.
If the window management policy is "focus follows mouse", it is enough to move the pointer out of the treeview window to lose the edit; if the policy is "click to focus", clicking anywhere outside of the treeview loses the edit.

This seems very counter-intuitive.  When you see it happen you think "Wha...?!"

Steps to reproduce:
1. Start gtk-demo, and activate the Editable Cells item.
2. Start editing the "bottles of coke" cell
3. Move the pointer out of the treeview window (focus follows mouse)
4. The edit is gone
5. Put the pointer back in the treeview: the edit is still gone


Actual results:
The treeview cell in question reverts to its original content.

Expected results:
The cell retains its state (edit in progress), in face of pointer movement
in and out of the treeview window.  

Does this happen every time?
Yes.

Other information: