[FIX] stock: Inventory Adjustments Deletion

It's not allowed to delete inventory adjustement linked to validated moves.

opw:1826300

addons/stock/i18n/stock.pot

@@ -6647,6 +6647,12 @@ msgstr ""
 msgid "You cannot delete a scrap which is done."
 msgstr ""
 
+#. module: stock
+#: code:addons/stock/models/stock_inventory.py:103
+#, python-format
+msgid "You cannot delete a validated inventory adjustement."
+msgstr ""
+
 #. module: stock
 #: code:addons/stock/models/stock_inventory.py:374
 #, python-format

addons/stock/models/stock_inventory.py

@@ -96,6 +96,13 @@ class Inventory(models.Model):
         else:
             self.total_qty = 0
 
+    @api.multi
+    def unlink(self):
+        for inventory in self:
+            if inventory.state == 'done':
+                raise UserError(_('You cannot delete a validated inventory adjustement.'))
+        return super(Inventory, self).unlink()
+
     @api.model
     def _selection_filter(self):
         """ Get the list of filter allowed according to the options checked