[FIX] stock: negative move propagation

When a warehouse used multi-steps for incoming/outgoing shipments,
negative procurements could create returns pickings instead of reducing
the quantity of subsequent moves down the chain.

For example a two-step delivery, a sale order with 5 product A would
have the following pickings linked :
Pick:
- product A : 5 qty
Out:
- product A : 5 qty

Then reducing the amount of product A to 2 in the sale order would do :
Pick:
- product A : 2 qty
Out:
- product A : 5 qty
Return:
- product A : 3 qty

closes odoo/odoo#84900

X-original-commit: c9bc689468d2c775d3b3ec65c8894e4dd66e7249
Signed-off-by: Arnold Moyaux <arm@odoo.com>

addons/sale_stock/tests/test_sale_stock.py

@@ -1122,8 +1122,11 @@ class TestSaleStock(TestSaleCommon, ValuationReconciliationTestCommon):
 
     def test_17_qty_update_propagation(self):
         """ Creates a sale order, then modifies the sale order lines qty and verifies
-        that quantity changes are correctly propagated to the delivery picking.
+        that quantity changes are correctly propagated to the picking and delivery picking.
         """
+        # Set the delivery in two steps.
+        warehouse = self.company_data['default_warehouse']
+        warehouse.delivery_steps = 'pick_ship'
         # Sell a product.
         product = self.company_data['product_delivery_no']    # storable
         product.type = 'product'    # storable
@@ -1138,8 +1141,10 @@ class TestSaleStock(TestSaleCommon, ValuationReconciliationTestCommon):
         sale_order.action_confirm()
 
         # Check picking created
-        self.assertEqual(len(sale_order.picking_ids), 1, 'A delivery picking should have been created.')
-        move_out = sale_order.picking_ids.move_ids
+        self.assertEqual(len(sale_order.picking_ids), 2, 'A picking and a delivery picking should have been created.')
+        customer_location = self.env.ref('stock.stock_location_customers')
+        move_pick = sale_order.picking_ids.filtered(lambda p: p.location_dest_id.id != customer_location.id).move_ids
+        move_out = sale_order.picking_ids.filtered(lambda p: p.location_dest_id.id == customer_location.id).move_ids
         self.assertEqual(len(move_out), 1, 'Only one move should be created for a single product.')
         self.assertEqual(move_out.product_uom_qty, 50, 'The move quantity should be the same as the quantity sold.')
 
@@ -1149,7 +1154,9 @@ class TestSaleStock(TestSaleCommon, ValuationReconciliationTestCommon):
                 (1, sale_order.order_line.id, {'product_uom_qty': 30}),
             ]
         })
-        self.assertEqual(move_out.product_uom_qty, 30, 'The move quantity should have been decreased as the sale order line was.')
+        self.assertEqual(move_pick.product_uom_qty, 30, 'The move quantity should have been decreased as the sale order line was.')
+        self.assertEqual(move_out.product_uom_qty, 30, 'The move quantity should have been decreased as the sale order line and the pick line were.')
+        self.assertEqual(len(sale_order.picking_ids), 2, 'No additionnal picking should have been created.')
 
         # Increase the quantity in the sale order and check the move has been updated.
         sale_order.write({
@@ -1157,4 +1164,5 @@ class TestSaleStock(TestSaleCommon, ValuationReconciliationTestCommon):
                 (1, sale_order.order_line.id, {'product_uom_qty': 40})
             ]
         })
-        self.assertEqual(move_out.product_uom_qty, 40, 'The move quantity should have been increased as the sale order line was.')
+        self.assertEqual(move_pick.product_uom_qty, 40, 'The move quantity should have been increased as the sale order line was.')
+        self.assertEqual(move_out.product_uom_qty, 40, 'The move quantity should have been increased as the sale order line and the pick line were.')

addons/stock/models/stock_move.py

@@ -6,7 +6,7 @@ from collections import defaultdict
 from datetime import timedelta
 from operator import itemgetter
 
-from odoo import _, api, fields, models
+from odoo import _, api, Command, fields, models
 from odoo.exceptions import UserError
 from odoo.osv import expression
 from odoo.tools.float_utils import float_compare, float_is_zero, float_round
@@ -878,6 +878,10 @@ class StockMove(models.Model):
                 # If quantity can be fully absorbed by a single move, update its quantity and remove the negative move
                 if float_compare(pos_move.product_uom_qty, abs(neg_move.product_uom_qty), precision_rounding=pos_move.product_uom.rounding) >= 0:
                     pos_move.product_uom_qty += neg_move.product_uom_qty
+                    pos_move.write({
+                        'move_dest_ids': [Command.link(m.id) for m in self.mapped('move_dest_ids')],
+                        'move_orig_ids': [Command.link(m.id) for m in self.mapped('move_orig_ids')],
+                    })
                     merged_moves |= pos_move
                     moves_to_unlink |= neg_move
                     break