This patch adds a new date field for record the invoice creation date and make Sales Invoice invoice number (which is a serial) readonly to guarantee the gapless invoice serial number.
Here is the video how does it work: http://youtu.be/uthH1m9swdg
In some countries the invoice creation date is required, especially when the computer generates the invoice. In other countries, where it is not necessary, it does not effect anything, free to set. It has no effect on the ledger or financial data.
Gapless invoice serial number in case of Sales Invoice: also, this strict rule guarantees that, the user cannot create custom computer generated sales invoice, but an auto-generated gapless, serial number. Any other cases (AR transaction, AP invoice/transaction etc.) this invoice number still free to set as usual.
In general these strict rules can help to use the system in more countries without too much issues.
In the video you can see, how to deal with Invoice Created Date field in various situation.
You can list in transactions, change the order of the list.
You can print the invoice including this invoice creation date.
You cannot change the date when the sales invoice generated by the software (aka you sell something via sales invoice).
You can change in any other cases.
You cannot change the invoice number when the sales invoice generated by the software (aka you sell something via sales invoice).
You can change the invoice number in any other cases.
I will commit it soon, so, you can test it by checkout the latest svn of 1.3 branch.
Please file a bug report to sourceforge if you found something weird.