From d611e66093ab5485018a9b48287a253ec947b9f0 Mon Sep 17 00:00:00 2001
From: iddo <iddo.aviram@similarweb.com>
Date: Tue, 12 Jan 2016 21:47:41 +0200
Subject: [PATCH] Bug fix: The get_prev API crashed when last day of month
 token was used. Some essential logic was missing.

---
 src/croniter/croniter.py            |  6 +++-
 src/croniter/tests/test_croniter.py | 43 +++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/croniter/croniter.py b/src/croniter/croniter.py
index eabb241..0f9d468 100644
--- a/src/croniter/croniter.py
+++ b/src/croniter/croniter.py
@@ -271,6 +271,8 @@ class croniter(object):
                 days = DAYS[month - 1]
                 if month == 2 and self.is_leap(year) is True:
                     days += 1
+                if 'l' in expanded[2] and days==d.day:
+                    return False, d
 
                 if is_prev:
                     days_in_prev_month = DAYS[
@@ -387,8 +389,10 @@ class croniter(object):
         candidates = to_check[:]
         candidates.reverse()
         for d in candidates:
-            if d <= x:
+            if d != 'l' and d <= x:
                 return d - x
+        if 'l' in candidates:
+            return -x
         candidate = candidates[0]
         for c in candidates:
             if c < range_val:
diff --git a/src/croniter/tests/test_croniter.py b/src/croniter/tests/test_croniter.py
index f8ac6f6..0baa9c0 100755
--- a/src/croniter/tests/test_croniter.py
+++ b/src/croniter/tests/test_croniter.py
@@ -180,6 +180,49 @@ class CroniterTest(base.TestCase):
         self.assertEqual(n4.month, 12)
         self.assertEqual(n4.day, 31)
 
+    def testPrevLastDayOfMonth(self):
+        base = datetime(2009, 12, 31, hour=20)
+        itr = croniter('0 0 l * *', base)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 12)
+        self.assertEqual(n1.day, 31)
+
+        base = datetime(2009, 12, 31)
+        itr = croniter('0 0 l * *', base)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 11)
+        self.assertEqual(n1.day, 30)
+
+        base = datetime(2010, 1, 5)
+        itr = croniter('0 0 l * *', base)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 12)
+        self.assertEqual(n1.day, 31)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 11)
+        self.assertEqual(n1.day, 30)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 10)
+        self.assertEqual(n1.day, 31)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 9)
+        self.assertEqual(n1.day, 30)
+
+        base = datetime(2010, 1, 31, minute=2)
+        itr = croniter('* * l * *', base)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 1)
+        self.assertEqual(n1.day, 31)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 1)
+        self.assertEqual(n1.day, 31)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 12)
+        self.assertEqual(n1.day, 31)
+        n1 = itr.get_prev(datetime)
+        self.assertEqual(n1.month, 12)
+        self.assertEqual(n1.day, 31)
+
     def testError(self):
         itr = croniter('* * * * *')
         self.assertRaises(TypeError, itr.get_next, str)