[Zope] pb with attach file

[blondelle at abes.fr]

Hello,

Few months ago, I send my problem with attach file with Zope 2.6 and higher.
How I have no solution, I send again my problem which is described after --------

Thanks to help me

Frederique

---------------

I have created a zclass with zfile as basic class.
With this class, users could, via a web form, send an attached file if
they want.
With zope 2.5 (my previous version) if users don't attach a file, there
is no problem
with zope 2.10, if there is no file attached, I have an error message :
'file not specified". It seems that  attach  file is mandatory.

Here, the complete message from the events log :

Traceback (innermost last):
   Module ZPublisher.Publish, line 119, in publish
   Module ZPublisher.mapply, line 88, in mapply
   Module ZPublisher.Publish, line 42, in call_object
   Module OFS.DTMLMethod, line 144, in __call__
    - <DTMLMethod at /assistance/do_add>
    - URL: http://assistance.abes.fr/do_add/manage_main
    - Physical Path: /assistance/do_add
   Module DocumentTemplate.DT_String, line 476, in __call__
   Module DocumentTemplate.DT_With, line 76, in render
   Module DocumentTemplate.DT_Util, line 196, in eval
    - __traceback_info__: _
   Module <string>, line 1, in <expression>
   Module OFS.DTMLMethod, line 137, in __call__
    - <DTMLMethod at /assistance/Quest_susvp_add>
    - URL: http://assistance.abes.fr/Quest_susvp_add/manage_main
    - Physical Path: /assistance/Quest_susvp_add
   Module DocumentTemplate.DT_String, line 476, in __call__
   Module DocumentTemplate.DT_With, line 61, in render
   Module DocumentTemplate.DT_Util, line 196, in eval
    - __traceback_info__: REQUEST
   Module <string>, line 1, in <expression>
   Module ZClasses.ZClass, line 454, in createInObjectManager
   Module ZClasses.ZClass, line 485, in fromRequest
   Module ZPublisher.mapply, line 89, in mapply
   Module OFS.Image, line 120, in __init__
   Module OFS.Image, line 501, in _read_data
ValueError: File not specified