[Python-checkins] python/dist/src/Lib rexec.py,1.28.4.2,1.28.4.3

[gvanrossum@users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib
In directory usw-pr-cvs1:/tmp/cvs-serv27999

Modified Files:
      Tag: release21-maint
	rexec.py 
Log Message:
Backport (the relevant part of) rexec.py 1.41.

Address SF bug #577530: del __builtins__ breaks out of rexec

Using the suggestion there: add_module() forces __builtin__ back; this
fixes r_exec, r_eval, r_execfile.

This does not mean that rexec is now considered safe!  But for those
willing to take the risk, it's safer than before.  (Note that a safety
analysis of the code module would be wise if you plan to use the
interactive console for real -- I've only ever used it to play with
restricted mode.)


Index: rexec.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/rexec.py,v
retrieving revision 1.28.4.2
retrieving revision 1.28.4.3
diff -C2 -d -r1.28.4.2 -r1.28.4.3
*** rexec.py	31 May 2002 21:19:53 -0000	1.28.4.2
--- rexec.py	15 Sep 2002 06:18:29 -0000	1.28.4.3
***************
*** 262,268 ****
  
      def add_module(self, mname):
!         if self.modules.has_key(mname):
!             return self.modules[mname]
!         self.modules[mname] = m = self.hooks.new_module(mname)
          m.__builtins__ = self.modules['__builtin__']
          return m
--- 262,268 ----
  
      def add_module(self, mname):
!         m = self.modules.get(mname)
!         if m is None:
!             self.modules[mname] = m = self.hooks.new_module(mname)
          m.__builtins__ = self.modules['__builtin__']
          return m