Fixes a query-optimizer bug where pushing single-source WHERE predicates into the nullable side of an outer join changed semantics, causing .where(({ r }) => isUndefined(r?.payload)) after a leftJoin to keep all left rows by stripping matched right rows to undefined instead of filtering them out. This restores correct post-join filtering behavior for LEFT/RIGHT/FULL joins, adds targeted regression tests, and should prevent incorrect query results in affected join+filter patterns. Main concern is that reducing predicate pushdown on nullable join sides could impact performance or alter plans for some queries, so it’s worth watching for optimizer regressions and ensuring coverage across more complex outer-join/filter combinations.