I use to expand/collapse tree nodes in the tree view by mouse, by clicking the triangle. It stopped working in gtk git master after update to commit 6a8d494. The gtk3-demo works on the first shot, but when I keep it running in the background and return back to it then it stops responding to my expand/collapse requests as well.

Steps to reproduce:
a) run gtk3-demo
b) expand and collapse the "Entry" node by mouse - it works
c) Alt+Tab to the terminal where processed step a)
d) Alt+Tab back to gtk3-demo
e) cannot repeat b)

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I also noticed undesired behaviour, when I collapse a node which has subnodes collapsed, then expanding the parent node expands also children nodes. It didn't use to do it and I consider it a bug.

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The triangle animation moves here like a lazy dog :)

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(I can file separate bugs for each, but the first and the second are the only I really care about.)