Maxime,

As you may know; users should never change the company of a contact 
because the contact started to work for another company. The only valid 
reason [1] to change the company of a contact is because you fix a 
wrongly created record. And, for those that want to handle contacts that 
change of companies, we have the base_contact module for this.

Your problem is not related at all with the current discussion. It just 
points out a usability issue which is that a user may change the company 
of a contact for an invalid reason. Olivier proposed to put a warning to 
avoid this mistake for end-users. We don't want to put the field 
readonly as you sometimes have to change the company of an existing 
contact for a valid reason [1].


Anyway, your scenario gives wrong expectations in v6.1, v7 and Raphaël's 
branch.

In v6.1, after modification of Joël from Camptocamp to Akretion, the 
invoice has the following fields:
     . Partner: Camptocamp
     . Invoice Address: Joël, Akretion
     . Contact Address: Joël, Akretion
         --> inconsistencies

In Raphael's branch, the invoice has the following fields:
   - Partner: Camptocamp
   - Invoice Address: Joël, Akretion
         --> inconsistencies [2]

In v7:
   - Partner: Joël, Akretion
   - Partner Company: Akretion
         --> consistent, but probably not what the user expect

In these 3 versions, the invoice is sent to Akretion's address. (side 
note: In v6.1, as an opposite to the two others, it's sent to Akretion 
but with the title 'Camptocamp'.)

As a conclusion;
   - it's normal to have wrong expectations, if you record wrong data. 
But, if the change is for a valid reason [1], only v7 is consistent and 
correct after the change.
   - v7's data model ensure consistency in the data: it's not possible 
to have an invoice for a company whereas the address belongs to another 
company
   - Raphaël's branch is totally inconsistent: on the screen you see 
"Joël, Akretion", but when you print it, you see "Camptocamp"


[1] Two examples of a valid reason to change the company of the contact; 
1/ I record Joël by mistake for the AMCE company and I fix this to ACME 
later 2/ I have two customers "Camptocamp" and "Camptocamp SAS" in my DB 
and I want to merge these two customers. If you change the company for a 
valid reason, v7 does the expect behaviour, not v6.1, not Raphaels branch.

[2] The reason why you probably did not noticed that Raphaël's branch 
data are wrong is that it has another bug: printed invoices are always 
sent at the company address, not at the invoice address, even if you 
define an invoice address. Same for emails, it uses the generic company 
email. (try to send an invoice to <email address hidden>, you will probably 
never be paid as our leads are forwarded to partners :) So, on the 
screen you see "Joël, Akretion", but when you print it, you see 
"Camptocamp".



So, in my opinion, your example, even if it's not a valid scenario, 
plays largely in favor of v7.

Fabien


On 14/04/13 14:33, Maxime Chambreuil (http://www.savoirfairelinux.com) 
wrote:
> @ Fabien
>
> I just updated my odony branch and here is the scenario I tested :
>
> Create Customers with :
> Camptocamp
>      Joël
> Akretion
>      Raphaël
>
> Create a SO for Joël, confirm it and generate the invoice.
> Group invoices by partner ->  CamptoCamp : 1 invoice
>
> Go to Joël and change his company to Akretion.
> Group invoice by partner ->  Akretion: 1 invoice
>
> You will tell me that this is normal to you, because your customer is
> Joël not C2C, right ? You want to handle B2C, but this scenario is B2B
> and you can't handle it with your solution.
>
> So, now your turn, download rvalyi's branch and test this scenario, assuming that:
> - if C2C is the customer, I don't change the partner_id field on the SO and the invoice will remain for C2C after Joël's transfer.
> - IfJoël is the customer, you change the partner_id back to Joël on the SO and the invoice will always belong to Joël.
>