[FIX] stock: do not merge mts and mto moves together

When we have two moves of the same product and procurement method
different on both, we don't want to merge them, because if a mto and a
mts move are merged together, it is possible to wait for an incoming
that will nerver come as a part the merged move should be taken from
stock

addons/stock/models/stock_move.py

@@ -517,7 +517,7 @@ class StockMove(models.Model):
     @api.model
     def _prepare_merge_moves_distinct_fields(self):
         return [
-            'product_id', 'price_unit', 'product_packaging',
+            'product_id', 'price_unit', 'product_packaging', 'procure_method',
             'product_uom', 'restrict_partner_id', 'scrapped', 'origin_returned_move_id'
         ]
 
@@ -525,8 +525,8 @@ class StockMove(models.Model):
     def _prepare_merge_move_sort_method(self, move):
         move.ensure_one()
         return [
-            move.product_id.id, move.price_unit, move.product_packaging.id, move.product_uom.id,
-            move.restrict_partner_id.id, move.scrapped, move.origin_returned_move_id.id
+            move.product_id.id, move.price_unit, move.product_packaging.id, move.procure_method, 
+            move.product_uom.id, move.restrict_partner_id.id, move.scrapped, move.origin_returned_move_id.id
         ]
 
     def _merge_moves(self):

addons/stock/tests/test_move2.py

@@ -24,6 +24,7 @@ class TestPickShip(TestStockCommon):
             'location_id': self.pack_location,
             'location_dest_id': self.customer_location,
             'state': 'waiting',
+            'procure_method': 'make_to_order',
         })
 
         picking_pick = self.env['stock.picking'].create({
@@ -509,6 +510,26 @@ class TestPickShip(TestStockCommon):
         self.assertEqual(set(return_pick_picking.move_lines.move_orig_ids.ids), set((picking_pick.move_lines | return_pack_picking.move_lines).ids))
         self.assertEqual(len(return_pick_picking.move_lines.move_dest_ids), 0)
 
+    def test_merge_move_mto_mts(self):
+        """ Create 2 moves of the same product in the same picking with
+        one in 'MTO' and the other one in 'MTS'. The moves shouldn't be merged
+        """
+        picking_pick, picking_client = self.create_pick_ship()
+
+        self.MoveObj.create({
+            'name': self.productA.name,
+            'product_id': self.productA.id,
+            'product_uom_qty': 3,
+            'product_uom': self.productA.uom_id.id,
+            'picking_id': picking_client.id,
+            'location_id': self.stock_location,
+            'location_dest_id': self.customer_location,
+            'origin': 'MPS',
+            'procure_method': 'make_to_stock',
+        })
+        picking_client.action_confirm()
+        self.assertEqual(len(picking_client.move_lines), 2, 'Moves should not be merged')
+
 class TestSinglePicking(TestStockCommon):
     def test_backorder_1(self):
         """ Check the good behavior of creating a backorder for an available stock move.