[FIX] resource: return correct date when planning hours

Planning hours can be done forwards or backwards. In first case the
returned datetime should be the last one aka the date when the job is
finished. In second case it should be the first one, aka the date when
the job begins. Those are the dates user want to know and manipulate when
programming working hours.

addons/resource/models/resource.py

@@ -474,7 +474,11 @@ class ResourceCalendar(models.Model):
         """ Wrapper on _schedule_hours: return the beginning/ending datetime of
         an hours scheduling. """
         res = self._schedule_hours(hours, day_dt, compute_leaves, resource_id, default_interval)
-        return res and res[0][0] or False
+        if res and hours < 0.0:
+            return res[0][0]
+        elif res:
+            return res[-1][1]
+        return False
 
     @api.multi
     def schedule_hours(self, hours, day_dt=None,

addons/resource/tests/test_resource.py

@@ -273,6 +273,9 @@ class TestResource(TestResourceCommon):
             td += item[1] - item[0]
         self.assertEqual(seconds(td) / 3600.0, 40.0, 'resource_calendar: wrong hours scheduling')
 
+        res = self.calendar.schedule_hours_get_date(-40, day_dt=self.date1.replace(minute=0, second=0))
+        self.assertEqual(res, Datetime.from_string('2013-01-29 09:00:00'))
+
         # --------------------------------------------------
         # Test2: schedule hours forward
         # --------------------------------------------------
@@ -299,6 +302,9 @@ class TestResource(TestResourceCommon):
             td += item[1] - item[0]
         self.assertEqual(seconds(td) / 3600.0, 40.0, 'resource_calendar: wrong hours scheduling')
 
+        res = self.calendar.schedule_hours_get_date(40, day_dt=self.date1.replace(minute=0, second=0))
+        self.assertEqual(res, Datetime.from_string('2013-02-26 09:00:00'))
+
         res = self.calendar.schedule_hours(
             40, day_dt=self.date1.replace(minute=0, second=0),
             compute_leaves=True, resource_id=self.resource1_id
@@ -401,6 +407,11 @@ class TestResource(TestResourceCommon):
         # 7h30 -> 12h30 = 5 / 13h -> 14h = 1 / -> 6h
         self.assertEqual(res, 6, 'resource_calendar: wrong get_working_hours computation')
 
+    def test_45_calendar_hours_scheduling_minutes(self):
+        """ Testing minutes computation in calendar hours scheduling """
+        res = self.calendar.schedule_hours_get_date(-39, day_dt=self.date1.replace(minute=25, second=20))
+        self.assertEqual(res, Datetime.from_string('2013-01-29 10:25:20'))
+
     def test_50_calendar_schedule_days(self):
         """ Testing calendar days scheduling """