Simplify logic of passing local scope to magics that need it.

Just use an argument rather than setting more global state.

IPython/core/interactiveshell.py

@@ -2023,21 +2023,21 b' class InteractiveShell(SingletonConfigurable):'
         if next_input:
             self.set_next_input(next_input)
 
-        magic_name, _, magic_args = arg_s.partition(' ')
+        magic_name, _, magic_arg_s = arg_s.partition(' ')
         magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
 
         fn = self.find_magic(magic_name)
         if fn is None:
             error("Magic function `%s` not found." % magic_name)
         else:
-            magic_args = self.var_expand(magic_args, 1)
+            magic_arg_s = self.var_expand(magic_arg_s, 1)
+            # Put magic args in a list so we can call with f(*a) syntax
+            args = [magic_arg_s]
             # Grab local namespace if we need it:
             if getattr(fn, "needs_local_scope", False):
-                self._magic_locals = sys._getframe(1).f_locals
+                args.append(sys._getframe(1).f_locals)
             with self.builtin_trap:
-                result = fn(magic_args)
-            # Ensure we're not keeping object references around:
-            self._magic_locals = {}
+                result = fn(*args)
             return result
 
     def define_magic(self, magic_name, func):

IPython/core/magic.py

@@ -2017,7 +2017,7 b' Currently the magic system has the following functions:\\n"""'
 
     @skip_doctest
     @needs_local_scope
-    def magic_time(self,parameter_s = ''):
+    def magic_time(self,parameter_s, user_locals):
         """Time execution of a Python statement or expression.
 
         The CPU and wall clock times are printed, and the value of the
@@ -2084,19 +2084,17 b' Currently the magic system has the following functions:\\n"""'
             tc = clock()-t0
         # skew measurement as little as possible
         glob = self.shell.user_ns
-        locs = self._magic_locals
-        clk = clock2
         wtime = time.time
         # time execution
         wall_st = wtime()
         if mode=='eval':
-            st = clk()
-            out = eval(code, glob, locs)
-            end = clk()
+            st = clock2()
+            out = eval(code, glob, user_locals)
+            end = clock2()
         else:
-            st = clk()
-            exec code in glob, locs
-            end = clk()
+            st = clock2()
+            exec code in glob, user_locals
+            end = clock2()
             out = None
         wall_end = wtime()
         # Compute actual times and report