[FIX] mrp: error w/o traceback on create BoM

If a Bill of Material is created without code (eg. when created as a new
group from a kanban view grouped by BoM) we would get a traceback
instead of an error.

With this changeset, we get a "You cannot create a new Bill of Material
from here." error if it is being tried.

opw-2124162
fix #38904
closes #40289

closes odoo/odoo#40457

X-original-commit: 32c13cd7d1387c0ea81a9bb5968d18c2b8f32051
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

addons/mrp/i18n/mrp.pot

@@ -4711,6 +4711,12 @@ msgid ""
 "numbers encoded."
 msgstr ""
 
+#. module: mrp
+#: code:addons/mrp/models/mrp_bom.py:0
+#, python-format
+msgid "You cannot create a new Bill of Material from here."
+msgstr ""
+
 #. module: mrp
 #: code:addons/mrp/models/mrp_unbuild.py:0
 #, python-format

addons/mrp/models/mrp_bom.py

@@ -121,6 +121,13 @@ class MrpBom(models.Model):
         for line in self.bom_line_ids:
             line.operation_id = False
 
+    @api.model
+    def name_create(self, name):
+        # prevent to use string as product_tmpl_id
+        if isinstance(name, str):
+            raise UserError(_("You cannot create a new Bill of Material from here."))
+        return super(MrpBom, self).name_create(name)
+
     def name_get(self):
         return [(bom.id, '%s%s' % (bom.code and '%s: ' % bom.code or '', bom.product_tmpl_id.display_name)) for bom in self]