[FIX] mrp: Avoid creating new line when changing qty to produce

When we change quantity to produce in mrp, all component lines are
removed and new line with the updated amount to product are created.
The problem appears when we change the quantity to produce and directly
click on a component line, because we open the line that will be
deleted. So if we change the quantity for this component manually,
this suppressed line will be added with the new value. And the computed
line will be also be added. So the line for one component will be
present twice (one with computed value and one with manual entry value).

To avoid this problem, when we change the quantity to produce, we update
information of each line (instead of deleting and creating new one).
So if we click on a component line just after changing the quantity,
we open the updated line (and not de deleted one).

addons/mrp/models/mrp_production.py

@@ -397,6 +397,7 @@ class MrpProduction(models.Model):
     def _onchange_bom_id(self):
         self.product_qty = self.bom_id.product_qty
         self.product_uom_id = self.bom_id.product_uom_id.id
+        self.move_raw_ids = [(2, move.id) for move in self.move_raw_ids.filtered(lambda m: m.bom_line_id)]
 
     @api.onchange('date_planned_start')
     def _onchange_date_planned_start(self):
@@ -409,11 +410,21 @@ class MrpProduction(models.Model):
 
     @api.onchange('bom_id', 'product_id', 'product_qty', 'product_uom_id')
     def _onchange_move_raw(self):
-        self.move_raw_ids = [(2, move.id) for move in self.move_raw_ids.filtered(lambda m: m.bom_line_id)]
         if self.bom_id and self.product_qty > 0:
+            # keep manual entries
+            list_move_raw = [(4, move.id) for move in self.move_raw_ids.filtered(lambda m: not m.bom_line_id)]
             moves_raw_values = self._get_moves_raw_values()
+            move_raw_dict = {move.bom_line_id.id: move for move in self.move_raw_ids.filtered(lambda m: m.bom_line_id)}
             for move_raw_values in moves_raw_values:
-                self.move_raw_ids += self.env['stock.move'].new(move_raw_values)
+                if move_raw_values['bom_line_id'] in move_raw_dict:
+                    # update existing entries
+                    list_move_raw += [(1, move_raw_dict[move_raw_values['bom_line_id']].id, move_raw_values)]
+                else:
+                    # add new entries
+                    list_move_raw += [(0, 0, move_raw_values)]
+            self.move_raw_ids = list_move_raw
+        else:
+            self.move_raw_ids = [(2, move.id) for move in self.move_raw_ids.filtered(lambda m: m.bom_line_id)]
 
     @api.onchange('location_src_id', 'move_raw_ids', 'routing_id')
     def _onchange_location(self):