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]).

IPython/core/interactiveshell.py

@@ -2455,9 +2455,6 @@ def safe_execfile(self, fname, *where, **kw):
         dname = os.path.dirname(fname)
 
         with prepended_to_syspath(dname):
-            # Ensure that __file__ is always defined to match Python behavior
-            save_fname = self.user_ns.get('__file__',None)
-            self.user_ns['__file__'] = fname
             try:
                 py3compat.execfile(fname,*where)
             except SystemExit as status:
@@ -2478,8 +2475,6 @@ def safe_execfile(self, fname, *where, **kw):
                 if kw['raise_exceptions']:
                     raise
                 self.showtraceback()
-            finally:
-                self.user_ns['__file__'] = save_fname
 
     def safe_execfile_ipy(self, fname):
         """Like safe_execfile, but for .ipy files with IPython syntax.
@@ -2506,9 +2501,6 @@ def safe_execfile_ipy(self, fname):
         dname = os.path.dirname(fname)
 
         with prepended_to_syspath(dname):
-            # Ensure that __file__ is always defined to match Python behavior
-            save_fname = self.user_ns.get('__file__',None)
-            self.user_ns['__file__'] = fname
             try:
                 with open(fname) as thefile:
                     # self.run_cell currently captures all exceptions
@@ -2519,8 +2511,6 @@ def safe_execfile_ipy(self, fname):
             except:
                 self.showtraceback()
                 warn('Unknown failure executing file: <%s>' % fname)
-            finally:
-                self.user_ns['__file__'] = save_fname
 
     def safe_run_module(self, mod_name, where):
         """A safe version of runpy.run_module().

IPython/core/shellapp.py

@@ -277,12 +277,20 @@ def _exec_file(self, fname):
             sys.argv = [ py3compat.cast_bytes(a) for a in sys.argv ]
         try:
             if os.path.isfile(full_filename):
-                self.log.info("Running file in user namespace: %s" % full_filename)
                 if full_filename.endswith('.ipy'):
+                    self.log.info("Running file in user namespace: %s" %
+                                  full_filename)
                     self.shell.safe_execfile_ipy(full_filename)
                 else:
                     # default to python, even without extension
-                    self.shell.safe_execfile(full_filename, self.shell.user_ns)
+                    self.log.info("Running file in user namespace: %s" %
+                                  full_filename)
+                    # Ensure that __file__ is always defined to match Python behavior
+                    self.shell.user_ns['__file__'] = fname
+                    try:
+                        self.shell.safe_execfile(full_filename, self.shell.user_ns)
+                    finally:
+                        del self.shell.user_ns['__file__']
         finally:
             sys.argv = save_argv