Ability to add to Items already in Shelves

If you have the same item in your hand that the shelf does, then instead of swapping the two items, it should instead add to the item. This would make shelves more convenient and user friendly!

This is because currently when a Shelf has an item with an incomplete stack, if you wish to add to that stack of the same item, it swaps the item on the shelf with the item in your hand. So, if you want to add to the stack in the shelf you have to take the item off of the shelf, then combine the two items in your inventory into one singular stack. Then you can put the combined items back onto the shelf.

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(E.G.) You just got back from a mining trip and wish to put your newly found 8 diamonds alongside your other 16 diamonds. You go up to the shelf with your diamonds and click (or shift-click). Instead of swapping the two stacks and having 16 diamonds in hand and 8 on the shelf. There would be 24 diamonds on the shelf.

Questions / Issues with this that may need to be addressed

Q. What happens when you overflow the item stack? You add 32 diamonds to a stack of 60 diamonds on the shelf, would you have 28 in hand, and 64 on the shelf?

Q. How would this work with powered shelves? Would it try and fill all the items in the powered shelf? Or would it only work with unpowered shelves?

Q. Method of interaction? Players may still want to swap a big stack for a small stack and not fill the item stack in the shelf. So Shift-Click instead of normal click to add?

Sorry for being wordy! Thank for reading!