[ocb-6.1] Failing test in purchase_double_validation

2013-10-25 00:52:38,223 8571 INFO 6-1-ocb-23520-all openerp.modules.loading: module purchase_double_validation: loading test/purchase_double_validation_demo.yml
...
2013-10-25 00:52:38,586 8571 TEST 6-1-ocb-23520-all openerp.tools.yaml_import: In order to test the flow, I confirmed the purchase order.
2013-10-25 00:52:38,641 8571 TEST 6-1-ocb-23520-all openerp.tools.yaml_import: I check that the order which was initially in the draft state has transmit to confirm state for double validation it should not an Approve state.
2013-10-25 00:52:38,643 8571 TEST 6-1-ocb-23520-all openerp.tools.yaml_import: I Approved the purchase order.
2013-10-25 00:52:38,717 8571 ERROR 6-1-ocb-23520-all openerp.tools.yaml_import: global name '_' is not defined
  File "/home/odoo/runbot/static/ocb-6-1-ocb-23520/server/openerp/addons/purchase/purchase.py", line 366, in action_invoice_create
    acc_id = self._choose_account_from_po_line(cr, uid, po_line, context=context)
  File "/home/odoo/runbot/static/ocb-6-1-ocb-23520/server/openerp/addons/account_anglo_saxon/purchase.py", line 36, in _choose_account_from_po_line
    raise osv.except_osv(_('Error !'), _('There is no stock input account defined for this product or category: "%s" (id:%d)') % (order_line.product_id.name, order_line.product_id.id,))
NameError: global name '_' is not defined

The error is misleading, of course. The culprit is a backport of http://bazaar.launchpad.net/~openerp/openobject-addons/trunk/revision/8787, but with an additional check on the availability of the stock input account. This account is not configured in the (nonexisting) demo data of account_anglo_saxon.