TargetSolver: use simple date arithmetics instead of createDateTimeFromMillis

Maybe this made sense long time ago, but nowadays we are using
equivalence testers which tolerate date differences with more flexibility.

createDateTimeFromMillis was also problematic as it uses internal
private attributes of DateTime which is a pylint error with more recent
DateTime

product/ERP5/TargetSolver/CopyToTarget.py

@@ -28,6 +28,8 @@ from __future__ import absolute_import
 #
 ##############################################################################
 
+import datetime
+from DateTime import DateTime
 from .TargetSolver import TargetSolver
 
 class CopyToTarget(TargetSolver):
@@ -60,13 +62,11 @@ class CopyToTarget(TargetSolver):
     quantity_ratio = 0
     if old_quantity not in (None,0.0): # XXX: What if quantity happens to be an integer ?
       quantity_ratio = new_quantity / old_quantity
-    start_date_delta = 0
-    stop_date_delta = 0
-    # get the date delta in milliseconds, to prevent rounding issues
+    stop_date_delta = start_date_delta = datetime.timedelta()
     if new_start_date is not None and old_start_date is not None:
-      start_date_delta = new_start_date.millis() - old_start_date.millis()
+      start_date_delta = new_start_date.asdatetime() - old_start_date.asdatetime()
     if new_stop_date is not None and old_stop_date is not None:
-      stop_date_delta = new_stop_date.millis() - old_stop_date.millis()
+      stop_date_delta = new_stop_date.asdatetime() - old_stop_date.asdatetime()
     return {
       'quantity_ratio': quantity_ratio,
       'start_date_delta': start_date_delta,
@@ -87,15 +87,14 @@ class CopyToTarget(TargetSolver):
     """
       Generate values to save on simulation movement.
     """
-    from erp5.component.module.DateUtils import createDateTimeFromMillis
     value_dict = {}
     # Modify quantity, start_date, stop_date
     start_date = simulation_movement.getStartDate()
     if start_date is not None:
-      value_dict['start_date'] = createDateTimeFromMillis(start_date.millis() + start_date_delta)
+      value_dict['start_date'] = DateTime(start_date.asdatetime() + start_date_delta)
     stop_date = simulation_movement.getStopDate()
     if stop_date is not None:
-      value_dict['stop_date'] = createDateTimeFromMillis(stop_date.millis() + stop_date_delta)
+      value_dict['stop_date'] = DateTime(stop_date.asdatetime() + stop_date_delta)
     value_dict['quantity'] = simulation_movement.getQuantity() * quantity_ratio
     return value_dict
 

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

@@ -453,30 +453,6 @@ def convertDateToHour(date=None):
   hour_ = (ordinal_date - ordinal_reference_date) * number_of_hours_in_day + number_of_hours_in_day + date.hour()
   return int(hour_)
 
-def createDateTimeFromMillis(millis): # pylint: disable=redefined-outer-name
-  """
-  Returns a DateTime object, build from the number of milliseconds since epoch.
-  Parameter should be a int or long.
-
-  This one should be used by solvers, as DateTime.__cmp__ actually only
-  compares the _millis parameter of the two DateTime objects.
-
-  This is currently not perfect: DateTime only supports creating a new object
-  from a floating point number of seconds since epoch, so a rounding issue is
-  still possible, that's why _millis is explicitely set to the same value
-  after the DateTime object has been created from (millis / 1000.)
-
-  A better way would be to compute (yr,mo,dy,hr,mn,sc,tz,t,d,s,millisecs) from
-  millis, and then create the DateTime object from it (see "elif ac == 11:" in
-  DateTime._parse_args).
-
-  Another solution would be a DateTime implementation that relies exclusively
-  on integer values internally.
-  """
-  millis = long(millis)
-  date = DateTime(millis / 1000.)
-  date._millis = millis
-  return date
 
 def getNumberOfDayInMonth(date):
   month = date.month()