Summary:
Items when shift + click are not moved to the stack, but to the first empty slot. This bug is not present in version 1.18.31.

Steps to reproduce:

1. Place a barrel/chest/shulker box.
2. Place a stackable item in the second slot.
3. Take item of the same type into your inventory.
4. Shift+click on a repair to move it out of inventory.

Observed results:
Items are not moved to the stack, but are moved to the first empty slot.

Expected results:
Items must move into a stack.

Video:
1.19.0.28/29 Minecraft Preview 2022-04-29 01-31-20.mp4
1.18.31 Minecraft 2022-04-29 01-33-38.mp4