Fix negative timedelta conversions

pony/converting.py

@@ -201,13 +201,14 @@ def _extract_time_parts(groupdict):
     return int(hh), int(mm or 0), int(ss or 0), int(mcs)
 
 def str2timedelta(s):
+    negative = s.startswith('-')
     if '.' in s:
         s, fractional = s.split('.')
         microseconds = int((fractional + '000000')[:6])
     else: microseconds = 0
     h, m, s = imap(int, s.split(':'))
     td = timedelta(hours=abs(h), minutes=m, seconds=s, microseconds=microseconds)
-    return -td if h < 0 else td
+    return -td if negative else td
 
 def timedelta2str(td):
     total_seconds = td.days * (24 * 60 * 60) + td.seconds

pony/orm/tests/test_conversions.py

@@ -0,0 +1,67 @@
+import unittest
+from datetime import timedelta
+
+from pony import converting
+
+class Test(unittest.TestCase):
+    def test_timestamps_1(self):
+        s = '1:2:3'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=1, minutes=2, seconds=3))
+        s = '01:02:03'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=1, minutes=2, seconds=3))
+        s = '1:2:3.456'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=1, minutes=2, seconds=3, milliseconds=456))
+        s = '1:2:3.45678'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=1, minutes=2, seconds=3, microseconds=456780))
+        s = '12:34:56'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=12, minutes=34, seconds=56))
+        s = '12:34:56.789'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=12, minutes=34, seconds=56, milliseconds=789))
+        s = '12:34:56.789123'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(hours=12, minutes=34, seconds=56, microseconds=789123))
+
+    def test_timestamps_2(self):
+        s = '-1:2:3'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=1, minutes=2, seconds=3))
+        s = '-01:02:03'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=1, minutes=2, seconds=3))
+        s = '-1:2:3.456'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=1, minutes=2, seconds=3, milliseconds=456))
+        s = '-1:2:3.45678'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=1, minutes=2, seconds=3, microseconds=456780))
+        s = '-12:34:56'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=12, minutes=34, seconds=56))
+        s = '-12:34:56.789'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=12, minutes=34, seconds=56, milliseconds=789))
+        s = '-12:34:56.789123'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(hours=12, minutes=34, seconds=56, microseconds=789123))
+
+    def test_timestamps_3(self):
+        s = '0:1:2'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(minutes=1, seconds=2))
+        s = '0:1:2.3456'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, timedelta(minutes=1, seconds=2, microseconds=345600))
+
+    def test_timestamps_4(self):
+        s = '-0:1:2'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(minutes=1, seconds=2))
+        s = '-0:1:2.3456'
+        td = converting.str2timedelta(s)
+        self.assertEqual(td, -timedelta(minutes=1, seconds=2, microseconds=345600))