File: workaround that io.BytesIO.tell() returns long on PY2

Unlike StringIO.StringIO().tell() and open().tell(), which all return
int, io.BytesIO().tell() returns long. Because io.BytesIO is used when
uploading files on Zope4, this cause PropertySheetValidity errors when
checking consistency, because Data.size property is expected to be int.

product/ERP5/bootstrap/erp5_core/DocumentTemplateItem/portal_components/document.erp5.File.py

@@ -27,6 +27,7 @@
 #
 ##############################################################################
 
+import six
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type.Base import WorkflowMethod
 from Products.ERP5Type import Permissions, PropertySheet
@@ -150,6 +151,12 @@ class File(Document, OFS_File):
       data.seek(0)
       self.manage_upload(data)
 
+  security.declarePrivate('update_data')
+  def update_data(self, *args, **kw):
+    super(File, self).update_data(*args, **kw)
+    if six.PY2 and isinstance(self.size, long):
+      self.size = int(self.size)
+
   security.declareProtected(Permissions.ModifyPortalContent,'setFile')
   def setFile(self, data, precondition=None):
     self._setFile(data, precondition=precondition)