[Python-checkins] cpython (2.7): Fix the total_ordering decorator to handle cross-type comparisons

Sat Mar 19 04:47:05 CET 2011

http://hg.python.org/cpython/rev/94c158199277
changeset: 68672:94c158199277
branch: 2.7
parent: 68651:e78e35954fbf
user: Éric Araujo <merwok at netwok.org>
date: Sat Mar 19 04:29:36 2011 +0100
summary:
 Fix the total_ordering decorator to handle cross-type comparisons
that could lead to infinite recursion (closes #10042).
files:
 Lib/functools.py
 Lib/test/test_functools.py
 Misc/ACKS
 Misc/NEWS

diff --git a/Lib/functools.py b/Lib/functools.py
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -53,17 +53,17 @@
 def total_ordering(cls):
 """Class decorator that fills in missing ordering methods"""
 convert = {
- '__lt__': [('__gt__', lambda self, other: other < self),
- ('__le__', lambda self, other: not other < self),
+ '__lt__': [('__gt__', lambda self, other: not (self < other or self == other)),
+ ('__le__', lambda self, other: self < other or self == other),
 ('__ge__', lambda self, other: not self < other)],
- '__le__': [('__ge__', lambda self, other: other <= self),
- ('__lt__', lambda self, other: not other <= self),
+ '__le__': [('__ge__', lambda self, other: not self <= other or self == other),
+ ('__lt__', lambda self, other: self <= other and not self == other),
 ('__gt__', lambda self, other: not self <= other)],
- '__gt__': [('__lt__', lambda self, other: other > self),
- ('__ge__', lambda self, other: not other > self),
+ '__gt__': [('__lt__', lambda self, other: not (self > other or self == other)),
+ ('__ge__', lambda self, other: self > other or self == other),
 ('__le__', lambda self, other: not self > other)],
- '__ge__': [('__le__', lambda self, other: other >= self),
- ('__gt__', lambda self, other: not other >= self),
+ '__ge__': [('__le__', lambda self, other: (not self >= other) or self == other),
+ ('__gt__', lambda self, other: self >= other and not self == other),
 ('__lt__', lambda self, other: not self >= other)]
 }
 roots = set(dir(cls)) & set(convert)
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -361,6 +361,8 @@
 self.value = value
 def __lt__(self, other):
 return self.value < other.value
+ def __eq__(self, other):
+ return self.value == other.value
 self.assertTrue(A(1) < A(2))
 self.assertTrue(A(2) > A(1))
 self.assertTrue(A(1) <= A(2))
@@ -375,6 +377,8 @@
 self.value = value
 def __le__(self, other):
 return self.value <= other.value
+ def __eq__(self, other):
+ return self.value == other.value
 self.assertTrue(A(1) < A(2))
 self.assertTrue(A(2) > A(1))
 self.assertTrue(A(1) <= A(2))
@@ -389,6 +393,8 @@
 self.value = value
 def __gt__(self, other):
 return self.value > other.value
+ def __eq__(self, other):
+ return self.value == other.value
 self.assertTrue(A(1) < A(2))
 self.assertTrue(A(2) > A(1))
 self.assertTrue(A(1) <= A(2))
@@ -403,6 +409,8 @@
 self.value = value
 def __ge__(self, other):
 return self.value >= other.value
+ def __eq__(self, other):
+ return self.value == other.value
 self.assertTrue(A(1) < A(2))
 self.assertTrue(A(2) > A(1))
 self.assertTrue(A(1) <= A(2))
@@ -428,6 +436,22 @@
 class A:
 pass
 
+ def test_bug_10042(self):
+ @functools.total_ordering
+ class TestTO:
+ def __init__(self, value):
+ self.value = value
+ def __eq__(self, other):
+ if isinstance(other, TestTO):
+ return self.value == other.value
+ return False
+ def __lt__(self, other):
+ if isinstance(other, TestTO):
+ return self.value < other.value
+ raise TypeError
+ with self.assertRaises(TypeError):
+ TestTO(8) <= ()
+
 def test_main(verbose=None):
 test_classes = (
 TestPartial,
diff --git a/Misc/ACKS b/Misc/ACKS
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -669,6 +669,7 @@
 Steven Reiz
 Roeland Rengelink
 Tim Rice
+Francesco Ricciardi
 Jan Pieter Riegel
 Armin Rigo
 Nicholas Riley
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -43,6 +43,9 @@
 Library
 -------
 
+- Issue #10042: Fixed the total_ordering decorator to handle cross-type
+ comparisons that could lead to infinite recursion.
+
 - Issue #10979: unittest stdout buffering now works with class and module
 setup and teardown.
 
-- 
Repository URL: http://hg.python.org/cpython
