[FIX] base: allow a user to attach documents to his profile, without administration access rights

The res.users class contains special fields that bypass access rights.
These are designed to allow a user that does not have the possibility to write
on res.users to modify their own fields, such as the mail signature.
Create and write are overriden to make it so, however the check_access_rights
isn't.
Since this method does not work at field level but at model level, there is no
easy way to resolve the incoherence.

Uploadding an image to a signature would add an attachment to the signature;
before being created, an attachment checks if the user has the rights to write
on the target model. The incoherence thus make it fail.

We add a special case when creating an attachment so that a user can write on
itself.

opw 1871243

0 files changed, 0 insertions, 0 deletions