[fix] when the last line in draft of the statement is confirmed, the statement should be confirmed only after passing the usual balance check, if the check is enabled in the profile. I add a test that shows the bug

account_statement_cancel_line/__openerp__.py

@@ -64,6 +64,7 @@
     'demo_xml': [],
     'test': [
         'test/cancel_line.yml',
+        'test/test_confirm_last_line_balance_check.yml',
         'test/test_confirm_last_line_no_balance_check.yml',
     ],
     'installable': True,

account_statement_cancel_line/statement.py

@@ -95,4 +95,10 @@ class Statement(orm.Model):
                     'state': 'confirm'
                 }, context=context)
                 need_to_update_view = True
+                self.balance_check(
+                    cr,
+                    uid,
+                    statement.id,
+                    journal_type=statement.journal_id.type,
+                    context=context)
         return need_to_update_view

account_statement_cancel_line/test/test_confirm_last_line_balance_check.yml

@@ -0,0 +1,42 @@
+-
+  I want to check that the behaviour when I confirm the only line of a
+  statement that is draft.
+-
+  I start with a profile
+-
+  !record {model: account.statement.profile, id: profile_test3}:
+    name: Profile for automatic checks
+    balance_check: True
+    journal_id: account.bank_journal
+    commission_account_id: account.a_expense
+-
+  Now I create a statement.
+-
+  !record {model: account.bank.statement, id: statement_test3}:
+    name: My Statement
+    profile_id: profile_test3
+    company_id: base.main_company
+    balance_start: 100.0
+    balance_end_real: 150.0
+-
+  I create a statement line
+-
+  !record {model: account.bank.statement.line, id: statement_line_3}:
+    name: line1
+    statement_id: statement_test3
+    ref: line1
+    date: '2014-01-20'
+    amount: 10.0
+-
+  Now I confirm the statement line. That should not pass the balance check
+-
+  !python {model: account.bank.statement.line}: |
+    # i.e. assertRaises 
+    from openerp.osv.osv import except_osv
+    try:
+        self.confirm(cr, uid, [ref("statement_line_3")])
+    except except_osv as exc:
+        print exc.args
+        assert u'The statement balance is incorrect' in exc.args[1], 'We got an error which is not what we expected'
+    else:
+        raise AssertionError('Balance check should have blocked this.')