The issue is simply creating a related stored many2many field, which is
pretty easy to do with Studio. When creating the field, Odoo crashes
with a traceback caused by ondelete being None on the field.
The source of the bug is the fact that the attribute field.ondelete is
set to a sensible default ('cascade') on non-related fields only. The
fix consists in setting the default value on the attribute itself, so
that the setup of the field never falls on a case where field.ondelete
is unset.
closesodoo/odoo#86303
X-original-commit: d0e0d80806a1b63ac986e9bcbaf88f9fc5243319
Signed-off-by: Raphael Collet <rco@odoo.com>