[FIX] account: base field in account.invoice.tax

The field base is obligatory according to a european law.
This field existed in saas-6.

opw:674713

addons/account/models/account_invoice.py

@@ -1233,6 +1233,14 @@ class AccountInvoiceTax(models.Model):
     _description = "Invoice Tax"
     _order = 'sequence'
 
+    def _compute_base_amount(self):
+        for tax in self:
+            base = 0.0
+            for line in tax.invoice_id.invoice_line_ids:
+                if tax.tax_id in line.invoice_line_tax_ids:
+                    base += line.price_subtotal
+            tax.base = base
+
     invoice_id = fields.Many2one('account.invoice', string='Invoice', ondelete='cascade', index=True)
     name = fields.Char(string='Tax Description', required=True)
     tax_id = fields.Many2one('account.tax', string='Tax')
@@ -1243,6 +1251,9 @@ class AccountInvoiceTax(models.Model):
     sequence = fields.Integer(help="Gives the sequence order when displaying a list of invoice tax.")
     company_id = fields.Many2one('res.company', string='Company', related='account_id.company_id', store=True, readonly=True)
     currency_id = fields.Many2one('res.currency', related='invoice_id.currency_id', store=True, readonly=True)
+    base = fields.Monetary(string='Base', compute='_compute_base_amount')
+
+
 
 
 class AccountPaymentTerm(models.Model):

addons/account/views/account_invoice_view.xml

@@ -93,6 +93,7 @@
                     <field name="manual"/>
                     <field name="name"/>
                     <field name="account_id" groups="base.group_account_user"/>
+                    <field name="base"/>
                     <field name="amount"/>
                     <field name="currency_id" invisible="1"/>
                 </tree>
@@ -111,6 +112,7 @@
                         <field name="account_analytic_id" domain="[('company_id', '=', parent.company_id), ('account_type', '=', 'normal')]" groups="analytic.group_analytic_accounting"/>
                         <field name="manual"/>
                         <field name="amount"/>
+                        <field name="base"/>
                         <field name="currency_id" invisible="1"/>
                     </group>
                 </form>

addons/account/views/report_invoice.xml

@@ -122,12 +122,17 @@
                         <thead>
                             <tr>
                                 <th>Tax</th>
+                                <th class="text-right">Base</th>
                                 <th class="text-right">Amount</th>
                             </tr>
                         </thead>
                         <tbody>
                             <tr t-foreach="o.tax_line_ids" t-as="t">
                                 <td><span t-field="t.name"/></td>
+                                <td class="text-right">
+                                    <span t-field="t.base"
+                                        t-field-options='{"widget": "monetary", "display_currency": "o.currency_id"}'/>
+                                </td>
                                 <td class="text-right">
                                     <span t-field="t.amount"
                                         t-field-options='{"widget": "monetary", "display_currency": "o.currency_id"}'/>