[6.0 & trunk] Invoice line get account of product without invoice.company contemplation

[Moisés López - http://www.vauxoo.com]

1) Steps to reproduce the issue you have observed
     Login with "admin" user
     Install multi_company module with demo data
     Set company "OpenERP US" to "admin" user
     Set account configuration to a product & partner
     Set company "OpenERP BE" to "admin" user
     Set account configuration to a product & partner with company
     Set company "OpenERP Corp" to "admin" user
     Create new invoice
     Set invoice.company to "OpenERP US"
     Set invoice.jounal of company "OpenERP US"
     Set invoice.partner_id (same with configuration of account)
     Here all fine. It will set invoice.account_id correctly with configuration of company (invoice.company)
     Now, Create a invoice_line & set product_id (same with configuration of account)
2) The result you observed
     It will set invoice_line.account_id from product_id with configuration user.company
3) The result you expected
     It will set invoice_line.account_id from product_id with configuration of invoice.company
4) The platform your are using
     Ubuntu11
5) The OpenERP version you are using (e.g. 5.0.15, 6.0-dev), if possible including the specific revision (e.g. rev. 2824) if you take the sources directly from Bazaar
  OpenERP-6.0
  Revno addons - 5004