Merge "Raise ValueError for offset on Timestamp over limit"

2 files changed, 18 insertions, 0 deletions

diff --git a/swift/common/utils.py b/swift/common/utils.py
index 239d7f067..a6633a9cd 100644
--- a/swift/common/utils.py
+++ b/swift/common/utils.py
@@ -587,6 +587,7 @@ def drop_buffer_cache(fd, offset, length):
 
 NORMAL_FORMAT = "%016.05f"
 INTERNAL_FORMAT = NORMAL_FORMAT + '_%016x'
+MAX_OFFSET = (16 ** 16) - 1
 # Setting this to True will cause the internal format to always display
 # extended digits - even when the value is equivalent to the normalized form.
 # This isn't ideal during an upgrade when some servers might not understand
@@ -647,6 +648,8 @@ class Timestamp(object):
             self.offset += offset
         else:
             raise ValueError('offset must be non-negative')
+        if self.offset > MAX_OFFSET:
+            raise ValueError('offset must be smaller than %d' % MAX_OFFSET)
 
     def __repr__(self):
         return INTERNAL_FORMAT % (self.timestamp, self.offset)
diff --git a/test/unit/common/test_utils.py b/test/unit/common/test_utils.py
index e62abc45d..87a136270 100644
--- a/test/unit/common/test_utils.py
+++ b/test/unit/common/test_utils.py
@@ -163,6 +163,21 @@ class TestTimestamp(unittest.TestCase):
         t = utils.Timestamp(time.time())
         self.assertRaises(TypeError, str, t)
 
+    def test_offset_limit(self):
+        t = 1417462430.78693
+        # can't have a offset above MAX_OFFSET
+        self.assertRaises(ValueError, utils.Timestamp, t,
+                          offset=utils.MAX_OFFSET + 1)
+        # exactly max offset is fine
+        ts = utils.Timestamp(t, offset=utils.MAX_OFFSET)
+        self.assertEqual(ts.internal, '1417462430.78693_ffffffffffffffff')
+        # but you can't offset it further
+        self.assertRaises(ValueError, utils.Timestamp, ts.internal, offset=1)
+        # unless you start below it
+        ts = utils.Timestamp(t, offset=utils.MAX_OFFSET - 1)
+        self.assertEqual(utils.Timestamp(ts.internal, offset=1),
+                         '1417462430.78693_ffffffffffffffff')
+
     def test_normal_format_no_offset(self):
         expected = '1402436408.91203'
         test_values = (