MultiSelect + DragDrop + TreeNode: Hovering over an open TreeNode with DragDrop active causes MultiSelect selection to be cleared and replaced by only the hovered TreeNode about imgui

[ocornut]

Thank for the detailed bug report, very much appreciated.
I have now pushed a fix for this: 2981a10, turns out it was pretty simple.

Note that the multi-select demos include an idea to traverse a tree linearly.

[ocornut]

While looking at your test case I was initially frustrated that double-clicking wouldn't open tree nodes.

Normal tree node open on simple click (could potentially be reevaluated) but when using multi-select we are forced to enable ImGuiTreeNodeFlags_OpenOnArrow. However I think we could come up with the change that if none of the _OpenOnXXX behavior is explicit, then the default for multi-selectable tree node would be ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick, aka a more sensible default. Going to make that change now.

[bratpilz]

Thanks for another very fast fix! This new default open behavior sounds good too. During my testing I had also noticed that I had to press on the arrow to open the nodes now, which wasn't super convenient, so this makes it easier.