When Sub 2 Task 26 flipped x_fc_internal_description to required=True,
any programmatic sale.order.line creation that doesn't set the field
fails at the Postgres NOT NULL constraint. Callers include:
- sale_mrp stock-move line creation (doesn't set name either)
- demo seeders
- external integrations
- test scripts
The UI-side onchange populates the field when the user picks a
description template; this hook mirrors that for programmatic callers.
Fallback chain: explicit vals['x_fc_internal_description'] → vals['name']
→ product_id.display_name → '—'. Matches the migration's backfill rule.
Also adds Sub 2 end-to-end smoke test (6 cases, all green):
1. Required-field rejection on part creation
2. Required-field rejection on template creation
3. Template picker populates both SO-line descriptions
4. Cert resolver: part-level override wins over partner
5. display_name renders part_number + revision + name
6. certificate_requirement defaults to 'inherit'
QC Phase 1-3 regression suite remains green after the fix.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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