[Zope-Checkins] CVS: Zope/lib/python/RestrictedPython - Guards.py:1.5.4.1

[Ken Manheimer]

Update of /cvs-repository/Zope/lib/python/RestrictedPython
In directory cvs.zope.org:/tmp/cvs-serv24340

Modified Files:
      Tag: Zope-2_4-branch
	Guards.py 
Log Message:
_full_read_guard(), _full_write_guard(): Use default arguments rather
than nested scopes to convey the value of safetype (and Wrapper, in
_full_write_guard()) to the nested guard function.

This is necessary to avoid occasional, apparent stack confusion in
_full_write_guard() when we use just nested scopes, where 'safetype'
gets the value of 'Wrapper'.  I don't know why this happens, or even
how to reliably repeat it with a simple case.  However, once the
conditions *are* set set, it's easy to repeat, and this change
prevents it from happening.


=== Zope/lib/python/RestrictedPython/Guards.py 1.5 => 1.5.4.1 ===
     # safetype variable is used by guard()
     safetype = {type(()): 1, type([]): 1, type({}): 1, type(''): 1}.has_key
-    def guard(ob, write=None):
+    def guard(ob, write=None, safetype=safetype):
         # Don't bother wrapping simple types, or objects that claim to
         # handle their own read security.
         if safetype(type(ob)) or getattr(ob, '_guarded_reads', 0):
@@ -165,7 +165,7 @@
     # safetype and Wrapper variables are used by guard()
     safetype = {type([]): 1, type({}): 1}.has_key
     Wrapper = _write_wrapper()
-    def guard(ob):
+    def guard(ob, safetype=safetype, Wrapper=Wrapper):
         # Don't bother wrapping simple types, or objects that claim to
         # handle their own write security.
         if safetype(type(ob)) or hasattr(ob, '_guarded_writes'):