The bug

Shift clicked items are not moved in other valid slots if the first slot the item would be valid for cannot take the item for example because it contains a different item, it contains already a full stack of the same item or the slot has special stacking restrictions.

Affected situations

Last updated for 19w34a

• Blaze powder in brewing stand being a valid ingredient and fuel ^{Fixed in 19w34a}
• Logs in furnace being valid item to smelt and fuel

How to reproduce

1. Place a brewing stand
2. Put a blaze powder item in your inventory
3. Open the brewing stand inventory and shift click the blaze powder
   → The blaze powder item moves into the ingredient slot
4. Place a different item in the ingredient slot
5. Shift click a blaze powder item
   → You will notice that it does not move despite it being a valid item for the fuel slot

Code analysis

Based on 1.11.2 decompiled using MCP 9.35 rc1

The methods overriding net.minecraft.inventory.Container.transferStackInSlot(EntityPlayer, int) return an empty item stack if an item is valid for a slot but cannot be placed in it, for example because there is already an item in the slot. Instead it should try all other valid slots before returning an empty item stack.