Fix date_parser with prefer_month_of_year wrong results

Fix two problems
1. Parser would use current month even if prefer_month_of_year was not
   current when relative_base was not none

2. Parser would use current month to derive 'what is the last day of
   this month' - for example, with prefer_month=last and
   prefer_day=past, but current_month=april, it would return december
   30th, because it would use april to find that the last day was the
   30th, when it should use the month.

Additionally, add a test to test_date_parser that uses prefer_month

dateparser/parser.py

@@ -598,10 +598,11 @@ def _correct_for_month(self, dateobj):
         relative_base_month = (
             relative_base.month if hasattr(relative_base, "month") else relative_base
         )
-        if getattr(self, "_token_month", None) or relative_base_month:
+
+        if getattr(self, "_token_month", None):
             return dateobj
 
-        dateobj = set_correct_month_from_settings(dateobj, self.settings)
+        dateobj = set_correct_month_from_settings(dateobj, self.settings, relative_base_month)
         return dateobj
 
     @classmethod
@@ -613,11 +614,13 @@ def parse(cls, datestring, settings, tz=None):
         # correction for past, future if applicable
         dateobj = po._correct_for_time_frame(dateobj, tz)
 
+        # correction for preference of month: beginning, current, end
+        # must happen before day so that day is derived from the correct month
+        dateobj = po._correct_for_month(dateobj)
+
         # correction for preference of day: beginning, current, end
         dateobj = po._correct_for_day(dateobj)
 
-        # correction for preference of month: beginning, current, end
-        dateobj = po._correct_for_month(dateobj)
         period = po._get_period()
 
         return dateobj, period

tests/test_date_parser.py

@@ -1265,6 +1265,63 @@ def test_prefer_dates_from_with_timezone(
         self.then_date_was_parsed_by_date_parser()
         self.then_date_obj_exactly_is(expected)
 
+
+    @parameterized.expand(
+        [
+            param(
+                "2015",
+                prefer_day="current",
+                prefer_month="current",
+                today=datetime(2010, 2, 10),
+                expected=datetime(2015, 2, 10),
+            ),
+            param(
+                "2015",
+                prefer_day="last",
+                prefer_month="current",
+                today=datetime(2010, 2, 10),
+                expected=datetime(2015, 2, 28),
+            ),
+            param(
+                "2015",
+                prefer_day="first",
+                prefer_month="current",
+                today=datetime(2010, 2, 10),
+                expected=datetime(2015, 2, 1),
+            ),
+            param(
+                "2015",
+                prefer_day="current",
+                prefer_month="last",
+                today=datetime(2010, 2, 10),
+                expected=datetime(2015, 12, 10),
+            ),
+            param(
+                "2015",
+                prefer_day="last",
+                prefer_month="last",
+                today=datetime(2010, 2, 10),
+                expected=datetime(2015, 12, 31),
+            ),
+            param(
+                "2020", #Leap year last day test
+                prefer_day="last",
+                prefer_month="current",
+                today=datetime(2010, 2, 10),
+                expected=datetime(2020, 2, 29),
+            ),
+        ]
+    )
+    def test_dates_with_no_day_or_month(
+        self, date_string, prefer_day, prefer_month, today=None, expected=None
+    ):
+        self.given_parser(
+            settings={"PREFER_DAY_OF_MONTH": prefer_day, "PREFER_MONTH_OF_YEAR": prefer_month, "RELATIVE_BASE": today}
+        )
+        self.when_date_is_parsed(date_string)
+        self.then_date_was_parsed_by_date_parser()
+        self.then_date_obj_exactly_is(expected)
+
     def given_local_tz_offset(self, offset):
         self.add_patch(
             patch.object(