ajshort/silverstripe-gridfieldextensions — pull request #56 by pitchandtone (2014-05-08 02:13:30+00:00)
Title: Update GridFieldOrderableRows.php

If it's a many many relationship, then it should be based on View not edit, as the sort field will be on the relationship using many_many_extraFields. Plus the view permission allows the user to create a many relationship, so it should allow editing of the relationship.