[TYPO3-commerce] Alert: be careful with billing.sourceFields

[Rik Willems]

Hi all,

I just ran into a problem which I'd like you all to know. For a client I 
wanted to add a field to the billing information screen, so customers 
could sign up to a newsletter.

Adding the field module_sys_dmail_newsletter to the setup worked fine, 
when using the appropriate hook. Fine as in the field was filled for the 
fe_user.

But, the same fields are used for adding tt_address records. And here 
things went south. New customers ended up placing records but got the 
wrong address attached, one of an existing customer. Probably due to 
error in adding the new address (tt_address doesn't have the 
module_sys_dmail_newsletter field).

Conclusion: be careful when adding new fields.

I added a condition around the typoscript config for this extra field, 
so that it isn't used in the finish step. This solves the problem.

Hope this is helpful.

Cheers!