[FIX] account_voucher: do not unlink records in onchange method

The method recompute_voucher_lines() is used by several onchange methods of
account.voucher.  It used to unlink() the voucher lines before recomputing new
voucher lines.  As a side effect, if you edit a voucher and discard your
changes, your voucher has lost its lines, although you did not save your
changes!  Moreover, the call to unlink() is invalidating the record cache,
which screws up completely the onchange() method.

So, instead of unlinking the existing lines, the onchange generates commands
[(2, id), ...] to remove the existing lines only when saving the changes.

diff --git a/addons/account_voucher/account_voucher.py b/addons/account_voucher/account_voucher.py
index 1bfd5dd..bf85884 100644 (file)
--- a/addons/account_voucher/account_voucher.py
+++ b/addons/account_voucher/account_voucher.py
@@ -187,9 +187,11 @@ class account_voucher(osv.osv):
         debit = credit = 0.0
         sign = type == 'payment' and -1 or 1
         for l in line_dr_ids:
-            debit += l['amount']
+            if isinstance(l, dict):
+                debit += l['amount']
         for l in line_cr_ids:
-            credit += l['amount']
+            if isinstance(l, dict):
+                credit += l['amount']
         return amount - sign * (credit - debit)
 
     def onchange_line_ids(self, cr, uid, ids, line_dr_ids, line_cr_ids, amount, voucher_currency, type, context=None):
@@ -565,6 +567,8 @@ class account_voucher(osv.osv):
             o2m_to_loop = 'line_dr_ids'
         if o2m_to_loop and 'value' in vals and o2m_to_loop in vals['value']:
             for voucher_line in vals['value'][o2m_to_loop]:
+                if not isinstance(voucher_line, dict):
+                    continue
                 if voucher_line['currency_id'] != currency_id:
                     # we take as default value for the payment_rate_currency_id, the currency of the first invoice that
                     # is not in the voucher currency
@@ -677,13 +681,16 @@ class account_voucher(osv.osv):
 
         #set default values
         default = {
-            'value': {'line_dr_ids': [] ,'line_cr_ids': [] ,'pre_line': False,},
+            'value': {'line_dr_ids': [], 'line_cr_ids': [], 'pre_line': False},
         }
 
-        #drop existing lines
-        line_ids = ids and line_pool.search(cr, uid, [('voucher_id', '=', ids[0])]) or False
-        if line_ids:
-            line_pool.unlink(cr, uid, line_ids)
+        # drop existing lines
+        line_ids = ids and line_pool.search(cr, uid, [('voucher_id', '=', ids[0])])
+        for line in line_pool.browse(cr, uid, line_ids, context=context):
+            if line.type == 'cr':
+                default['value']['line_cr_ids'].append((2, line.id))
+            else:
+                default['value']['line_dr_ids'].append((2, line.id))
 
         if not partner_id or not journal_id:
             return default