[FIX] mrp: update date on move when editing date after planning WO

Behavior prior to this commit:

 - normally when editing the Scheduled Date on a MO, the date on the
 related stock moves is updated.  However this does not happen once the
 MO is planned
 - if the date is edited and the MO is planned, the MO is automatically
 unplanned, but the date on the stock moves is not automatically updated

Behavior after this commit:

 - when the date is updated on the MO and it is planned, the dates on the
 stock moves will automatically update, so that the behavior is
 consistent with how it would work if you clicked Unplan first then
 updated the date.

Note:

 - this commit is forward ported from 14.0.  Only the unit test was
 ported, as the behavior had already been modified to match the
 expectation.

opw-2417108

closes odoo/odoo#64006

X-original-commit: 97f79960dbb3aa371378f576cfdce9670ca8ccce
Signed-off-by: Nicolas Galler <ngaller@users.noreply.github.com>

addons/mrp/tests/test_order.py

@@ -316,6 +316,22 @@ class TestMrpOrder(TestMrpCommon):
         production = mo_form.save()
         self.assertEqual(production.workorder_ids.duration_expected, 90)
 
+    def test_update_plan_date(self):
+        """Editing the scheduled date after planning the MO should unplan the MO, and adjust the date on the stock moves"""
+        planned_date = datetime(2023, 5, 15, 9, 0)
+        mo_form = Form(self.env['mrp.production'])
+        mo_form.product_id = self.product_4
+        mo_form.bom_id = self.bom_1
+        mo_form.product_qty = 1
+        mo_form.date_planned_start = planned_date
+        mo = mo_form.save()
+        self.assertEqual(mo.move_finished_ids[0].date, datetime(2023, 5, 15, 10, 0))
+        mo.action_confirm()
+        mo.button_plan()
+        with Form(mo) as frm:
+            frm.date_planned_start = datetime(2024, 5, 15, 9, 0)
+        self.assertEqual(mo.move_finished_ids[0].date, datetime(2024, 5, 15, 10, 0))
+
     def test_rounding(self):
         """ Checks we round up when bringing goods to produce and round half-up when producing.
         This implementation allows to implement an efficiency notion (see rev 347f140fe63612ee05e).