Access error when selecting party on invoice
A access error is raised when selecting a party on invoice when the following conditions are meet:
1. The database has multiple companies with multiple charts of account created.
2. The companies have defined a default receivable and payable account.
3. The party has no receivable/payable account defined and thus it uses the default values.
We've debugged the problem and found the that this is because the multivalue mixin returns the accounts of all companies, so when reading some value of the account all the instances are read (this is a tryton design to improve performance), and this breaks the access rules as the ids for other companies are read.