avoid error when file is not accessible, log error message instead

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3190 fd906abe-77d9-0310-91a1-e0d9ade77398

storage/filesystem.py

@@ -65,10 +65,16 @@ class FileSystemStorage(object):
     def getData(self, address, params={}):
         subDir = params.get('subdirectory')
         fn = self.getDir(address, subDir)
-        f = open(fn, 'rb')
-        data = f.read()
-        f.close()
-        return data
+        try:
+            f = open(fn, 'rb')
+            data = f.read()
+            f.close()
+            return data
+        except IOError, e:
+            from logging import getLogger
+            getLogger('cybertools.storage.filesystem.FileSystemStorage').warn(e)
+                        #'File %r cannot be read.' % fn)
+            return ''
 
     def getUniqueAddress(self, address, params={}):
         subDir = params.get('subdirectory')