The problem is caused by calling sym.members().dupUnshared() in JavacElements.getAllMembers(...). This call creates a Scope with the new member table that shares its entries with the original member table. Now, imagine the situation that original_table[i] points to Entry1 that shadows Entry2. By adding closure type members to the newly created Scope in the JavacElements.getAllMembers(...) a necessity for dble() the new member table may appear. During dble() all entries of a new table are rehashed so that new_table[j] now points to Entry1, new_table[k] points to Entry2 and the shadow link between Entry1 and Entry2 is removed. However, since the entries were shared between the original and new tables, the original_table[i] still points to Entry1 and the link to Entry2 is lost.