If pieces.empty is empty, it is bogus to access pieces[0]: sstring move_name = pieces[0]; Fix by adding the missing return. Spotted by Vlad Zolotarov <vladz@scylladb.com> Fixes #3258 Message-Id: <bcb446f34f953bc51c3704d06630b53fda82e8d2.1520297558.git.asias@scylladb.com>