4637207120
Summary: Iterator has a bug: if a child iterator reaches its end, and user issues a Prev(), and just before SeekToLast() of the child iterator is called, some extra rows is added in the end, the position of iterator can be misplaced. Test Plan: Run the tests with or without valgrind Reviewers: rven, yhchiang, IslamAbdelRahman, anthony Reviewed By: anthony Subscribers: tnovak, leveldb, dhruba Differential Revision: https://reviews.facebook.net/D43671