When shift-clicking an item in the inventory or in any container GUI, even if the item can stack with the item in the offhand slot, the game will not stack them.
For instance, if the player has torches in their offhand, and crafts more torches in the inventory or a crafting table, shift-clicking the crafted torches will place them in the hotbar or inventory rather than stacking them into the offhand slot.
This issue was previously reported nearly a year ago as MC-84345, but it was wrongly marked as a duplicate of MC-84224.
Linked issues
duplicates 1
Comments 4
Nope, you can't shift-click into a full inventory even when something could be stacked with the offhand item.
[media]Even if the inventory isn't full, the game will make a new stack in the hotbar/inventory rather than adding it to the offhand slot.
Reopened. Please update your ticket to only be about items not moving into the offhand slot when no other slot can be chosen, both while crafting and while moving items out of the inventory and the hotbar.
Actually a dupe of MC-85216
Shift-clicking items into the offhand slot while in container GUIs would be weird as the slot isn't actually displayed in the container GUI. For the regular inventory shift-clicking between main inventory and hotbar is preferred over shift-clicking into the offhand slot.
If anything, we could consider it a bug if shift-clicking a stack in a completely full (36 stacks) inventory wouldn't move it into the offhand slot. Does that work?