Dima Dorfman's patch for coercion/comparison of C types (patch #995939), with
a minor change after the coercion, to accept two objects not necessarily of
the same type but with the same tp_compare.
diff --git a/Lib/test/test_coercion.py b/Lib/test/test_coercion.py
index 331771f..37d735b 100644
--- a/Lib/test/test_coercion.py
+++ b/Lib/test/test_coercion.py
@@ -125,9 +125,45 @@
else:
print '=', format_result(x)
+# New-style class version of CoerceNumber
+class CoerceTo(object):
+ def __init__(self, arg):
+ self.arg = arg
+ def __coerce__(self, other):
+ if isinstance(other, CoerceTo):
+ return self.arg, other.arg
+ else:
+ return self.arg, other
+
+def assert_(expr, msg=None):
+ if not expr:
+ raise AssertionError, msg
+
+def do_cmptypes():
+ # Built-in tp_compare slots expect their arguments to have the
+ # same type, but a user-defined __coerce__ doesn't have to obey.
+ # SF #980352
+ evil_coercer = CoerceTo(42)
+ # Make sure these don't crash any more
+ assert_(cmp(u'fish', evil_coercer) != 0)
+ assert_(cmp(slice(1), evil_coercer) != 0)
+ # ...but that this still works
+ class WackyComparer(object):
+ def __cmp__(self, other):
+ assert_(other == 42, 'expected evil_coercer, got %r' % other)
+ return 0
+ assert_(cmp(WackyComparer(), evil_coercer) == 0)
+ # ...and classic classes too, since that code path is a little different
+ class ClassicWackyComparer:
+ def __cmp__(self, other):
+ assert_(other == 42, 'expected evil_coercer, got %r' % other)
+ return 0
+ assert_(cmp(ClassicWackyComparer(), evil_coercer) == 0)
+
warnings.filterwarnings("ignore",
r'complex divmod\(\), // and % are deprecated',
DeprecationWarning,
r'test.test_coercion$')
do_infix_binops()
do_prefix_binops()
+do_cmptypes()