Tree's button's tooltip error when set column title is visible

[CsloudX]

Tested versions

v4.2.1.stable.mono.official [b09f793]

System information

Godot v4.2.1.stable.mono - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 5GB (NVIDIA; 31.0.15.3623) - AMD Ryzen 9 3900X 12-Core Processor (24 Threads)

Issue description

Tree's button's tooltip error when set column tiltle visible

Steps to reproduce

.

Minimal reproduction project (MRP)

TreeTest.zip

[Illauriel]

Looks like the same bug broke AnimationLibraryEditor's button tooltips too.

Recording.2024-01-03.065407.mp4

It seems like a pretty big problem, because half the editor is different tree views.

I've pinpointed this bug to somewhere between 4.1 and 4.2, because it's present as early as 4.2-rc1
It definitely has to do with rect calculations in Tree::get_tooltip(), and I blame this commit 8278a5f, because if I replace that part of code with code from 4.1 branch, AnimationLibraryEditor tooltips work correctly.

[akien-mga]

Possibly regression from #79792 as per above comment, CC @Miguel0312 @KoBeWi @YuriSizov.

[KoBeWi]

I confirmed that regression comes from the mentioned PR (or at least reverting it fixes the bug), but couldn't figure out why does it happen. Something is wrong with item rects.

[CsloudX]

It like the text was error too when enabled treeitem editable.

[akien-mga]

Fixed by #90842.