[IMP] cow_templates_replicate_upstream: also update inherit_id

[cristina-hidalgo-tecnativa]

cow_templates_replicate_upstream only copies arch_db from the generic view to its COW'd copies, not inherit_id.

That's enough when a module migration only changes the content of the parent template, but not when the migration itself re-targets which template the view inherits from — the COW copy keeps the old inherit_id and view combination still fails at render time, even after arch_db is refreshed.

This showed up in a real migration: OCA/e-commerce#1295 restructures website_sale_product_attribute_filter_category's view because website_sale moved the attribute-filter loop to a different template between 18.0 and 19.0. A website that had the option toggled on in 18.0 kept crashing /shop after upgrading, because its COW copy still inherited from the old template.

The fix copies inherit_id along with arch_db, but first checks whether the new parent template itself has its own COW copy for that same website — if so, it points there instead of at the generic parent, preserving that website's own customization chain. When the parent didn't change, or there's no website-specific copy of it, it falls back to generic.inherit_id as before (no-op / same behavior as the initial version of this fix).

@Tecnativa TT64160
@pedrobaeza @pilarvargas-tecnativa

[pedrobaeza]

Wait, this is not correct at all. Maybe there's another parent specific for the website, and it should be set as the inherit. Can it be? Or am I wrong?

[pilarvargas-tecnativa]

I think the best approach would be:

• Get the new generic parent from generic.inherit_id.
• Look for a COW copy of that parent for the same website_id as the view being updated.
• If it exists, use that COW view as the new inherit_id.
• Otherwise, fall back to the generic parent.

This way we preserve the website-specific inheritance chain instead of always pointing the COW view directly to the generic parent.

[cristina-hidalgo-tecnativa]

I think the best approach would be:

* Get the new generic parent from generic.inherit_id.

* Look for a COW copy of that parent for the same website_id as the view being updated.

* If it exists, use that COW view as the new inherit_id.

* Otherwise, fall back to the generic parent.

This way we preserve the website-specific inheritance chain instead of always pointing the COW view directly to the generic parent.

Exactly, that's the approach I already pushed — get the generic parent's key, look for a COW copy of it for the same website_id, use that if it exists, otherwise fall back to the generic parent.

[pedrobaeza]

Now to apply these 2 methods in all the OpenUpgrade versions...