[FIX] stock: wrong result_package_id

When forcefully unreserving then reserving products coming from a same
package for multiple pickings, the source package is wrongly propagated
as destination package on the multiple pickings.

To reproduce:
 - `-i sale_stock,sale_management`
 - Create a storable product (I) with 30 qty on hand
 - Create and confirm an internal transfer to put the product I in an pack (P)
 - Create and confirm two SO :
   - Sell 10 I
   - Sell 20 I
 - Check the 2 SO delivery pickings (D):
   - Each are reserved from pack P
   - They don't have any 'Destination Package' [Expected]
 - From the picking list view, by selecting the 2 pickings D :
   - 'Unreserve' them both
   - 'Check Availability'them both
 - Check the pickings D:
   - Each are reserved from pack P
   - Each have 'Destination Package' P [Faulty]

opw-4272573

closes odoo#193745

Signed-off-by: Steve Van Essche <svs@odoo.com>

Author: mama-odoo

addons/stock/models/stock_picking.py

@@ -1034,9 +1034,9 @@ def _check_entire_pack(self):
                             'move_line_ids': [(6, 0, move_lines_to_pack.ids)],
                             'company_id': pickings.company_id.id,
                         })
-                    # Propagate the result package in the next move for disposable packages only.
-                    if package.package_use == 'disposable':
-                        move_lines_to_pack.write({'result_package_id': package.id})
+                        # Propagate the result package in the next move for disposable packages only.
+                        if package.package_use == 'disposable':
+                            move_lines_to_pack.write({'result_package_id': package.id})
                 else:
                     move_lines_in_package_level = move_lines_to_pack.filtered(lambda ml: ml.move_id.package_level_id)
                     move_lines_without_package_level = move_lines_to_pack - move_lines_in_package_level

addons/stock/tests/test_packing.py

@@ -1939,3 +1939,51 @@ def test_reusable_package_propagation(self):
         self.assertEqual(len(pack_lines), 2, 'Should have only 2 stock move line')
         self.assertFalse(pack_lines[0].result_package_id, 'Should not have the reusable package')
         self.assertEqual(pack_lines[1].result_package_id, disposable_package, 'Should have only the disposable package')
+
+    def test_conditional_package_propagation(self):
+        """If a picking completely moves the products of a package, you want to pass it as result_package_id.
+        On the other hand, if the quantity of the same pack is split between several pickings, you want to leave the result_package_id empty.
+        """
+        # Storable product : 30 qty in a package.
+        package = self.env['stock.quant.package'].create({'name': 'packtest'})
+        self.env['stock.quant']._update_available_quantity(self.productA, self.stock_location, 30.0, package_id=package)
+
+        # 1 delivery picking, 30 product, action_assign => On move line, package_id == result_package_id
+        full_delivery = self.env['stock.picking'].create({
+            'picking_type_id': self.warehouse.out_type_id.id,
+            'location_id': self.stock_location.id,
+            'location_dest_id': self.customer_location.id,
+            'move_ids': [Command.create({
+                'name': 'move full',
+                'product_id': self.productA.id,
+                'product_uom_qty': 30.0,
+                'product_uom': self.productA.uom_id.id,
+                'location_id': self.stock_location.id,
+                'location_dest_id': self.customer_location.id,
+            })]
+        })
+        full_delivery.action_confirm()
+        full_delivery.action_assign()
+        self.assertEqual(full_delivery.move_line_ids.package_id, package, "The package should be used as source.")
+        self.assertEqual(full_delivery.move_line_ids.result_package_id, package, "If all the products in a package are to be moved, we must move the entire package.")
+        full_delivery.action_cancel()  # Cancel delivery to unreserve the package/quantity.
+
+        # Create 2 delivery picking : 10 & 20 of product each.
+        partial_deliveries = self.env['stock.picking'].create([{
+            'picking_type_id': self.warehouse.out_type_id.id,
+            'location_id': self.stock_location.id,
+            'location_dest_id': self.customer_location.id,
+            'move_ids': [Command.create({
+                'name': 'move partial',
+                'product_id': self.productA.id,
+                'product_uom_qty': qty,
+                'product_uom': self.productA.uom_id.id,
+                'location_id': self.stock_location.id,
+                'location_dest_id': self.customer_location.id,
+            })]
+        } for qty in [10, 20]])
+        partial_deliveries.action_confirm()
+        partial_deliveries.action_assign()
+        # action_assign => On move lines, result_package_id is not set.
+        self.assertEqual(partial_deliveries.move_line_ids.package_id, package, "The package should be used as source.")
+        self.assertFalse(partial_deliveries.move_line_ids.result_package_id, "If the contents of a single pack are reserved by multiple picks, the entire pack can't reproduce on each pick.")