erp5_core: fix addToDate when removing a month

See merge request nexedi/erp5!1768

bt5/erp5_core_test/TestTemplateItem/portal_components/test.erp5.testDateUtils.py

@@ -62,6 +62,17 @@ class TestDateUtils(unittest.TestCase):
                               addToDate(date, month=90).toZone('UTC').ISO())
     self.assertEqual(DateTime('2090/01/01 %s' % self.timezone).toZone('UTC').ISO(),
                               addToDate(date, year=90).toZone('UTC').ISO())
+    april_1 = DateTime('2001/04/01 %s' % self.timezone)
+    self.assertEqual(DateTime('2001/05/01 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(april_1, month=1).toZone('UTC').ISO())
+    december_1 = DateTime('2001/12/01 %s' % self.timezone)
+    self.assertEqual(DateTime('2002/01/01 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(december_1, month=1).toZone('UTC').ISO())
+    march_31 = DateTime('2001/03/31 %s' % self.timezone)
+    self.assertEqual(DateTime('2001/04/30 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(march_31, month=1).toZone('UTC').ISO())
+    self.assertEqual(DateTime('2001/05/1 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(march_31, month=1, day=1).toZone('UTC').ISO())
 
   def test_negative_add_to_date(self):
     date = DateTime('2000/01/01 %s' % self.timezone)
@@ -77,6 +88,14 @@ class TestDateUtils(unittest.TestCase):
                               addToDate(date, month=-1).toZone('UTC').ISO())
     self.assertEqual(DateTime('1999/01/01 %s' % self.timezone).toZone('UTC').ISO(),
                               addToDate(date, year=-1).toZone('UTC').ISO())
+    march_31 = DateTime('2001/03/31 %s' % self.timezone)
+    self.assertEqual(DateTime('2001/02/28 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(march_31, month=-1).toZone('UTC').ISO())
+    self.assertEqual(DateTime('2001/02/27 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(march_31, month=-1, day=-1).toZone('UTC').ISO())
+    may_31 = DateTime('2000/05/31 %s' % self.timezone)
+    self.assertEqual(DateTime('2000/04/30 %s' % self.timezone).toZone('UTC').ISO(),
+                              addToDate(may_31, month=-1).toZone('UTC').ISO())
 
   def test_float_add_to_date(self):
     date = DateTime('2000/01/01 %s' % self.timezone)

product/ERP5/bootstrap/erp5_core/ModuleComponentTemplateItem/portal_components/module.erp5.DateUtils.py

@@ -110,6 +110,8 @@ def addToDate(date, to_add=None, **kw):
       return_value[larger_key_dict[key]] = return_value[larger_key_dict[key]] + 1
 
   for key in key_list:
+    if key == 'day':
+      continue
     if to_add.get(key, None) is not None:
       return_value[key] = return_value[key] + to_add[key]
       del to_add[key]
@@ -125,7 +127,12 @@ def addToDate(date, to_add=None, **kw):
         if local_key not in ('day', 'year'):
           treatPositiveValues(return_value, local_key)
 
-  day_to_add = return_value['day'] - 1
+  day_to_add = min(
+    return_value['day'],
+    getNumberOfDayInMonth(
+      DateTime(return_value['year'], int(return_value['month']), 1)
+    )
+  ) - 1
   if to_add.get('day', None) is not None:
     day_to_add += to_add['day']
   return_value['day'] = 1