When adding “free-form products” to quotes they do not have a product
ID, but i has coalescing the NULL to zero because product_id is an
integer and can not coalesce a nullable integer to an empty string.
However, that causes problems when trying to create the invoice for that
quote, because it tries to add products that have an ID of 0 and the
foreign key, obviously, fail.
At first i modified NewInvoiceProductArray.EncodeBinary to check for
"0" as well as the empty string, but i realized this was wrong: the
problem was because i gave these products an ID when they do not have
any. And the solution is to cast product_id to a text, which is what
will get converted anyway because i the only thing i do to it is to
store to a string-backed InputForm field.
Closes#73.
jordi fita mas
1c6375b51d