Sale and purchase taxes are not get from account.accout default tax

Default taxes defined in product's income or expense account (product_template.property_income_account and product_template.property_expense_account) does not work in sale orders or purchase orders.

The situation can be generated like this:

1) create product. Define income account bot does not define any taxes direct to the product.
2) Define default tax to income- and expense accounts related to the product
3) Create SO and select the product you created. There is on taxes on that SO.

Expected behavior would be that if there is no taxes defined in product, default taxes from income account should be used.

There is same situation with purchase orders as well.

This is a tricky situation when you are working with multi-company database since product tax definition is not property.

Proposed fix:

With following path taxes seems to be added as they should (in my point of view). There is fix for procurement process as well.
---
addons/purchase/purchase.py:
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>
>
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> prod_tpl = self.pool.get('product.template').browse(cr, uid, product)
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> context['company_id'] = self.browse(cr, uid, ids[0], context).company_id
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> taxes = prod.supplier_taxes_id or\
> prod_tpl.property_account_expense.tax_ids or\
> prod_tpl.categ_id.property_account_expense_categ.tax_ids
>
>
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< 'taxes_id':map(lambda x: x.id, prod.supplier_taxes_id),
---
> 'taxes_id': taxes,
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< taxes = self.pool.get('account.tax').browse(cr, uid,map(lambda x: x.id, prod.supplier_taxes_id))
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> prod_tpl = self.pool.get('product.template').browse(cr, uid, procurement.product_id.id, context=context)
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< taxes_ids = procurement.product_id.product_tmpl_id.supplier_taxes_id
---
> taxes_ids = prod_tpl.supplier_taxes_id or\
> prod_tpl.property_account_expense.tax_ids or\
> prod_tpl.property_account_expense_categ.tax_ids
---
---
addons/sale/sale.py

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> product_tpl = self.pool.get('product.template')
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> product_tpl = product_tpl.browse(cr, uid, product, context=context)
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> if not result['tax_id']:
> result['tax_id'] = self.pool.get('account.fiscal.position').map_tax(cr, uid, fpos, product_tpl.property_account_income.tax_ids)
> if not result['tax_id']:
> result['tax_id'] = self.pool.get('account.fiscal.position').map_tax(cr, uid, fpos, product_tpl.categ_id.property_account_income_categ.tax_ids)
---