Two expectations predate the reference-write analysis and return moves on this branch. `keep(item, items) { items.push(item); return item; }` now qualifies as a borrowed-return function: its write set (array elements) misses the walked parameter, so the body retains only the appended element, returns the parameter +0 while the caller still owns it, and the owned adapter retains the result before releasing its parameters. In `snapshot`, `return saved` moves the saved alias's owned scope entry into the result rather than retaining it again and releasing the local at scope exit, leaving one retain.
Malte Ubl
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