[MC-185121] Scroll bar in resource pack selection can get too long

Resize your Minecraft window to be smaller
Open the resource pack screen.
Move the bottom pack to the right
❌: The scroll bar will extend beyond where it should.

Linked issues

Thank you for your report!
However, this issue is a Duplicate of ~~MC-158271~~ MC-167167

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That's for resizing the window. This is a different cause.