Comment 1 for bug 1164460

Internal moves between companies should not be allowed.
Goods are owned by a company and there should be a sales document + purchase document + pickings and invoices between them to perform movement.

Sending goods from B to C should be performed like:

COMPANY B should create:
Sales order company B to customer C
Outgoing picking from company B to customer C
Invoice from company B to company C

---
COMPANY C should create:
Purchase order company C to company B
Incoming picking from company B to company C
Purchase invoice from company B to company C

Otherwise, there will not be a consistent transaction and inventory valuation would be wrong for both companies.

My 2 cents.