How to Fix a Stack-Split Dialog That Rounds Quantities Wrong

Splitting a stack of 7 with the slider sometimes yields 4 and 4, duplicating an item, or 3 and 3, losing one. Independent rounding is the cause. Here is how to fix it.

How to fix it

1. Round one side, subtract the other

Round the moved amount to an integer, then set remainder = total - moved instead of rounding it separately. The two always sum to the total.

2. Clamp the moved amount

Constrain the slider to 1..total-1 so a split always leaves at least one in each stack and cannot move zero or the whole stack.

3. Commit atomically

Apply the source decrement and destination increment in one operation so an interruption cannot leave the item count duplicated or lost.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.