Thousands of Poles who believed they were long divorced are discovering an unsettling possibility: They may still be legally married. The confusion is an unexpected upshot of Poland’s years-long battle over a politicized judiciary spilling into everyday life, as Prime Minister Donald Tusk’s centrist government tries to undo reforms of the legal system imposed by its nationalist predecessors. The problem surfaced in January in the northeastern town of Giżycko, where a divorced couple went to