fix: Use get_timedelta in cast, add to safe_exec list

* Return date and datetime objects for Date and Datetime field types
  respectively if Falsy output is set

frappe/utils/data.py

@@ -583,19 +583,19 @@ def cast(fieldtype, value=None):
 		value = cstr(value)
 
 	elif fieldtype == "Date":
-		if value is None:
+		if value:
+			value = getdate(value)
+		else:
 			value = datetime.datetime(1, 1, 1).date()
-		value = getdate(value)
 
 	elif fieldtype == "Datetime":
-		if value is None:
+		if value:
+			value = get_datetime(value)
+		else:
 			value = datetime.datetime(1, 1, 1)
-		value = get_datetime(value)
 
 	elif fieldtype == "Time":
-		if value is None:
-			value = "0:0:0"
-		value = to_timedelta(value)
+		value = get_timedelta(value)
 
 	return value
 

frappe/utils/safe_exec.py

@@ -228,6 +228,7 @@ VALID_UTILS = (
 "getdate",
 "get_datetime",
 "to_timedelta",
+"get_timedelta",
 "add_to_date",
 "add_days",
 "add_months",