[FIX] stock: action_done on move without quantity done

When we validate stock move having move lines with quanity done equal to
'0', these move lines are unreserved and in MRP, it creates move lines
with product_qty = 0 and qty_done = 0 which is not wanted

addons/stock/models/stock_move.py

@@ -892,7 +892,7 @@ class StockMove(models.Model):
                 qty_split = move.product_uom._compute_quantity(move.product_uom_qty - move.quantity_done, move.product_id.uom_id)
                 new_move = move.split(qty_split)
                 for move_line in move.move_line_ids:
-                    if move_line.product_qty:
+                    if move_line.product_qty and move_line.qty_done:
                         # FIXME: there will be an issue if the move was partially available
                         # By decreasing `product_qty`, we free the reservation.
                         # FIXME: if qty_done > product_qty, this could raise if nothing is in stock

addons/stock/tests/test_move.py

@@ -2716,3 +2716,36 @@ class StockMove(TransactionCase):
 
         self.assertEqual(self.product1.qty_available, 5.0)
         self.assertEqual(self.product1.with_context(company_owned=True).qty_available, 10.0)
+
+    def test_split_1(self):
+        """ When we split a move line and having one without quantity done, we want to keep reservation
+            on the new one as it has not been unreserved during the copy.
+        """
+        move1 = self.env['stock.move'].create({
+            'name': 'test_split_1',
+            'location_id': self.stock_location.id,
+            'location_dest_id': self.customer_location.id,
+            'product_id': self.product1.id,
+            'product_uom': self.uom_unit.id,
+            'product_uom_qty': 10.0,
+            'picking_type_id': self.env.ref('stock.picking_type_in').id,
+        })
+
+        self.env['stock.quant']._update_available_quantity(self.product1, self.stock_location, 10)
+
+        move1.action_confirm()
+        move1.action_assign()
+        move_line = move1.move_line_ids
+
+        default = {'product_uom_qty': 3,
+                   'qty_done': 3}
+        move_line.copy(default=default)
+        move_line.with_context(bypass_reservation_update=True).write({'product_uom_qty': 7, 'qty_done': 0})
+        move1.action_done()
+
+        new_move = self.env['stock.move'].search([('name', '=', 'test_split_1'), ('state', '=', 'confirmed')])
+
+        self.assertEqual(move1.move_line_ids.product_uom_qty, 0.0)
+        self.assertEqual(move1.move_line_ids.qty_done, 3.0)
+        self.assertEqual(new_move.move_line_ids.product_uom_qty, 7.0)
+        self.assertEqual(new_move.move_line_ids.qty_done, 0.0)