Merge 90ea12e into 9936469

.github/workflows/tests.yml

@@ -229,11 +229,9 @@ jobs:
         if: ${{ !startsWith(matrix.python-version, 'pypy') }}
         run: |
           python -m coverage run -p -m zope.testrunner --test-path=src --auto-color --auto-progress
-# This is not supported
-#      - name: Run tests without C extensions
-#        run:
-#          # coverage makes PyPy run about 3x slower!
-#          PURE_PYTHON=1 python -m coverage run -p -m zope.testrunner --test-path=src --auto-color --auto-progress
+      - name: Run tests without C extensions
+        run: |
+          AC_PURE_PYTHON=1 python -m coverage run -p -m zope.testrunner --test-path=src --auto-color --auto-progress
       - name: Report Coverage
         run: |
           coverage combine

CHANGES.rst

@@ -8,6 +8,8 @@ For changes before version 3.0, see ``HISTORY.rst``.
 
 - Provide ``AccessControl.get_safe_globals`` to facilitate safe use.
 
+- Use ``AC_PURE_PYTHON`` as switch to enable python implementation as default.
+  This should not be used except for tests and debugging.
 
 
 5.2 (2021-07-30)

src/AccessControl/ImplPython.py

@@ -76,8 +76,8 @@ def rolesForPermissionOn(perm, object, default=_default_roles, n=None):
             roles = getattr(object, n)
             if roles is None:
                 if _embed_permission_in_roles:
-                    return ('Anonymous', n)
-                return 'Anonymous'
+                    return (('Anonymous',), n)
+                return ('Anonymous',)
 
             t = type(roles)
             if t is tuple:

src/AccessControl/Implementation.py

@@ -25,6 +25,13 @@
 
 """
 from __future__ import absolute_import
+import os
+
+# We cannot use `PURE_PYTHON` as this would be propagated to `ExtensionClass`
+# and `Acquisition`. Due to restrictions of python implementation concerning
+# proxies it is not possible to run all with pure python and we influence only
+# the AccessControl implementation here.
+CAPI = not int(os.environ.get('AC_PURE_PYTHON', '0'))
 
 
 def getImplementationName():
@@ -96,7 +103,11 @@ def setImplementation(name):
                                          ),
 }
 
-setImplementation(_default_implementation)
+
+if CAPI:
+    setImplementation(_default_implementation)
+else:
+    setImplementation('PYTHON')
 
 # allow the implementation to change from the default
 _implementation_set = 0