Fixes an issue with the item handling when adding to a large stack of items. Because of deferred updating of stack counts, combined with the rollover logic to handle excess amounts, you'd get weird cases where 950 + 50 = 951, rather than 999 in one stack and 1 in another. The missing amount would be permanently lost, which is annoying even if you probably won't miss it if you have 999 of any one item.
Now when you're done "filling" a stack, you should revert to the "no target slot" behavior and dump into the next valid slot/stack.
Fixes an issue with the item handling when adding to a large stack of items. Because of deferred updating of stack counts, combined with the rollover logic to handle excess amounts, you'd get weird cases where 950 + 50 = 951, rather than 999 in one stack and 1 in another. The missing amount would be permanently lost, which is annoying even if you probably won't miss it if you have 999 of any one item.
Now when you're done "filling" a stack, you should revert to the "no target slot" behavior and dump into the next valid slot/stack.
Checklist:
develop
branch