From e680f29560ac20133c7af0c6364c6ef494662eac Mon Sep 17 00:00:00 2001
From: Nicolas Martinelli <nim@odoo.com>
Date: Mon, 25 Apr 2016 14:11:47 +0200
Subject: [PATCH] [FIX] account, sale: modify invoice

When a user validates an invoice linked to a SO, he might want to modify
it afterwards thanks to the 'Modify' option in the refund wizard. This
will create a refund, reconcile and create a draft invoice.

The issue is that the draft invoice is not linked with the SO.

The fix is to link, in this specific case only, the draft invoice to the
SO. At the same time, we have to make sure to:
- unlink the first invoice (to prevent counting the quantity as invoiced
  in the SO)
- keep track of the first invoice/refund in the invoice list of the SO

opw-673446
---
 addons/account/wizard/account_invoice_refund.py |  2 +-
 addons/sale/sale.py                             | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/addons/account/wizard/account_invoice_refund.py b/addons/account/wizard/account_invoice_refund.py
index 226b3e711f8..638b0e1fc1e 100644
--- a/addons/account/wizard/account_invoice_refund.py
+++ b/addons/account/wizard/account_invoice_refund.py
@@ -87,7 +87,7 @@ class AccountInvoiceRefund(models.TransientModel):
                         invoice = invoice[0]
                         del invoice['id']
                         invoice_lines = inv_line_obj.browse(invoice['invoice_line_ids'])
-                        invoice_lines = inv_obj._refund_cleanup_lines(invoice_lines)
+                        invoice_lines = inv_obj.with_context(mode='modify')._refund_cleanup_lines(invoice_lines)
                         tax_lines = inv_tax_obj.browse(invoice['tax_line_ids'])
                         tax_lines = inv_obj._refund_cleanup_lines(tax_lines)
                         invoice.update({
diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index 02b00c9680c..3bea2419718 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -52,6 +52,9 @@ class SaleOrder(models.Model):
         """
         for order in self:
             invoice_ids = order.order_line.mapped('invoice_lines').mapped('invoice_id')
+            # Search for invoices which have been 'cancelled' (filter_refund = 'modify' in
+            # 'account.invoice.refund')
+            invoice_ids |= invoice_ids.search([('origin', 'like', order.name)])
             # Search for refunds as well
             refund_ids = self.env['account.invoice'].browse()
             if invoice_ids:
@@ -835,6 +838,16 @@ class AccountInvoice(models.Model):
             order.message_post(body=_("Invoice %s paid") % (name))
         return res
 
+    @api.model
+    def _refund_cleanup_lines(self, lines):
+        result = super(AccountInvoice, self)._refund_cleanup_lines(lines)
+        if self.env.context.get('mode') == 'modify':
+            for i in xrange(0, len(lines)):
+                for name, field in lines[i]._fields.iteritems():
+                    if name == 'sale_line_ids':
+                        result[i][2][name] = [(6, 0, lines[i][name].ids)]
+                        lines[i][name] = False
+        return result
 
 class AccountInvoiceLine(models.Model):
     _inherit = 'account.invoice.line'