Log a warning when making a partial copy.

src/OFS/CopySupport.py

@@ -16,6 +16,7 @@
 from cgi import escape
 from marshal import dumps
 from marshal import loads
+import logging
 import re
 import sys
 import tempfile
@@ -61,8 +62,8 @@ class CopyError(Exception):
     pass
 
 copy_re = re.compile('^copy([0-9]*)_of_(.*)')
-
-_marker=[]
+logger = logging.getLogger('OFS')
+_marker = []
 
 
 class CopyContainer(Base):
@@ -607,6 +608,12 @@ class CopySource(Base):
                     # We do not use cp._delObject, because this would fire
                     # events that are needless for objects that are not even in
                     # an Acquisition chain yet.
+                    logger.warn(
+                        'While copying %s, removed %s from copy '
+                        'because user is not allowed to view the original.',
+                        '/'.join(self.getPhysicalPath()),
+                        '/'.join(v.getPhysicalPath())
+                    )
                     cp._delOb(k)
                     # We need to cleanup the internal objects list, even when
                     # in some implementations this is always an empty tuple.