Merge pull request #2432 from bfroehle/revert_1831 Revert #1831, the `__file__` injection in safe_execfile / safe_execfile_ipy. This reverts commit 2717feb, reversing changes made to ea4f608. Pull request #1831 (fix #1814 set __file__ when running .ipy files) has been the source of a lot of grief: #2279: Setting __file__ to None breaks Mayavi import #2429: Using warnings.warn() results in TypeError In general the patch was inappropriate because it: 1. Fails to properly restore the context, by setting __file__ to None rather than deleting it. 2. Sets __file__ in the wrong dictionary (self.user_ns rather than where[0]).