PICARD-2712: Fix sanitize date removing 0 values

Sanitize date cleared zero values in between, such turning "YYYY-00-DD"
into "YYYY-DD", which would be a completely different date.

Fix this by keeping empty values if they are not the last element.

picard/util/__init__.py

@@ -312,18 +312,23 @@ def format_time(ms, display_zero=False):
 def sanitize_date(datestr):
     """Sanitize date format.
 
-    e.g.: "YYYY-00-00" -> "YYYY"
-          "YYYY-  -  " -> "YYYY"
+    e.g.: "1980-00-00" -> "1980"
+          "1980-  -  " -> "1980"
+          "1980-00-23" -> "1980-00-23"
           ...
     """
     date = []
-    for num in datestr.split("-"):
+    for num in reversed(datestr.split("-")):
         try:
             num = int(num.strip())
         except ValueError:
-            break
-        if num:
+            if num == '':
+                num = 0
+            else:
+                break
+        if num or (num == 0 and date):
             date.append(num)
+    date.reverse()
     return ("", "%04d", "%04d-%02d", "%04d-%02d-%02d")[len(date)] % tuple(date)
 
 

test/test_utils.py

@@ -188,15 +188,26 @@ def test_mapping(self):
 class SanitizeDateTest(PicardTestCase):
 
     def test_correct(self):
+        self.assertEqual(util.sanitize_date(""), "")
+        self.assertEqual(util.sanitize_date("0"), "")
+        self.assertEqual(util.sanitize_date("0000"), "")
+        self.assertEqual(util.sanitize_date("2006"), "2006")
         self.assertEqual(util.sanitize_date("2006--"), "2006")
-        self.assertEqual(util.sanitize_date("2006--02"), "2006")
+        self.assertEqual(util.sanitize_date("2006-00-02"), "2006-00-02")
         self.assertEqual(util.sanitize_date("2006   "), "2006")
         self.assertEqual(util.sanitize_date("2006 02"), "")
         self.assertEqual(util.sanitize_date("2006.02"), "")
         self.assertEqual(util.sanitize_date("2006-02"), "2006-02")
+        self.assertEqual(util.sanitize_date("2006-02-00"), "2006-02")
+        self.assertEqual(util.sanitize_date("2006-00-00"), "2006")
+        self.assertEqual(util.sanitize_date("2006-02-23"), "2006-02-23")
+        self.assertEqual(util.sanitize_date("2006-00-23"), "2006-00-23")
+        self.assertEqual(util.sanitize_date("0000-00-23"), "0000-00-23")
+        self.assertEqual(util.sanitize_date("0000-02"), "0000-02")
+        self.assertEqual(util.sanitize_date("--23"), "0000-00-23")
 
     def test_incorrect(self):
-        self.assertNotEqual(util.sanitize_date("2006--02"), "2006-02")
+        self.assertNotEqual(util.sanitize_date("2006--02"), "2006")
         self.assertNotEqual(util.sanitize_date("2006.03.02"), "2006-03-02")