hooks: fix encoding problems of lock release ui messages The vcs test test_push_unlocks_repository_hg would fail when waitress tried to append a unicode chunk to the byte stream. The unicode string came from the 'Released lock on repo' message passed to ui.status from the push hook. ui.status do however follow the Mercurial convention and expects a byte string. We solve the problem by applying safe_str. Patch modified by Mads Kiilerich.