[Python-checkins] cpython (merge 3.5 -> default): Merge
raymond.hettinger
python-checkins at python.org
Wed Aug 31 18:01:40 EDT 2016
https://hg.python.org/cpython/rev/f23fc0f48ebe
changeset: 102978:f23fc0f48ebe
parent: 102975:fcf65749ef71
parent: 102977:5ae941fef3be
user: Raymond Hettinger <python at rcn.com>
date: Wed Aug 31 15:01:28 2016 -0700
summary:
Merge
files:
Lib/random.py | 7 +++++++
Lib/test/test_random.py | 18 ++++++++++++++++++
Misc/NEWS | 5 +++++
3 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/Lib/random.py b/Lib/random.py
--- a/Lib/random.py
+++ b/Lib/random.py
@@ -112,6 +112,13 @@
import time
a = int(time.time() * 256) # use fractional seconds
+ if version == 1 and isinstance(a, (str, bytes)):
+ x = ord(a[0]) << 7 if a else 0
+ for c in a:
+ x = ((1000003 * x) ^ ord(c)) & 0xFFFFFFFFFFFFFFFF
+ x ^= len(a)
+ a = -2 if x == -1 else x
+
if version == 2:
if isinstance(a, (str, bytes, bytearray)):
if isinstance(a, str):
diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py
--- a/Lib/test/test_random.py
+++ b/Lib/test/test_random.py
@@ -326,6 +326,24 @@
['0x1.1239ddfb11b7cp-3', '0x1.b3cbb5c51b120p-4',
'0x1.8c4f55116b60fp-1', '0x1.63eb525174a27p-1'])
+ def test_bug_27706(self):
+ # Verify that version 1 seeds are unaffected by hash randomization
+
+ self.gen.seed('nofar', version=1) # hash('nofar') == 5990528763808513177
+ self.assertEqual([self.gen.random().hex() for i in range(4)],
+ ['0x1.8645314505ad7p-1', '0x1.afb1f82e40a40p-5',
+ '0x1.2a59d2285e971p-1', '0x1.56977142a7880p-6'])
+
+ self.gen.seed('rachel', version=1) # hash('rachel') == -9091735575445484789
+ self.assertEqual([self.gen.random().hex() for i in range(4)],
+ ['0x1.0b294cc856fcdp-1', '0x1.2ad22d79e77b8p-3',
+ '0x1.3052b9c072678p-2', '0x1.578f332106574p-3'])
+
+ self.gen.seed('', version=1) # hash('') == 0
+ self.assertEqual([self.gen.random().hex() for i in range(4)],
+ ['0x1.b0580f98a7dbep-1', '0x1.84129978f9c1ap-1',
+ '0x1.aeaa51052e978p-2', '0x1.092178fb945a6p-2'])
+
def test_setstate_first_arg(self):
self.assertRaises(ValueError, self.gen.setstate, (1, None, None))
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -72,6 +72,11 @@
- Issue #19884: Avoid spurious output on OS X with Gnu Readline.
+- Issue #27706: Restore deterministic behavior of random.Random().seed()
+ for string seeds using seeding version 1. Allows sequences of calls
+ to random() to exactly match those obtained in Python 2.
+ Patch by Nofar Schnider.
+
- Issue #10513: Fix a regression in Connection.commit(). Statements should
not be reset after a commit.
--
Repository URL: https://hg.python.org/cpython
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