diff options
| -rw-r--r-- | Lib/test/test_hash.py | 11 | ||||
| -rw-r--r-- | Objects/longobject.c | 8 |
2 files changed, 19 insertions, 0 deletions
diff --git a/Lib/test/test_hash.py b/Lib/test/test_hash.py index 3d6c9d1..07b65da 100644 --- a/Lib/test/test_hash.py +++ b/Lib/test/test_hash.py @@ -18,10 +18,21 @@ class HashEqualityTestCase(unittest.TestCase): def test_numeric_literals(self): self.same_hash(1, 1L, 1.0, 1.0+0.0j) + self.same_hash(0, 0L, 0.0, 0.0+0.0j) + self.same_hash(-1, -1L, -1.0, -1.0+0.0j) + self.same_hash(-2, -2L, -2.0, -2.0+0.0j) def test_coerced_integers(self): self.same_hash(int(1), long(1), float(1), complex(1), int('1'), float('1.0')) + self.same_hash(int(-2**31), long(-2**31), float(-2**31)) + self.same_hash(int(1-2**31), long(1-2**31), float(1-2**31)) + self.same_hash(int(2**31-1), long(2**31-1), float(2**31-1)) + # for 64-bit platforms + self.same_hash(int(2**31), long(2**31), float(2**31)) + self.same_hash(int(-2**63), long(-2**63), float(-2**63)) + self.same_hash(int(1-2**63), long(1-2**63)) + self.same_hash(int(2**63-1), long(2**63-1)) def test_coerced_floats(self): self.same_hash(long(1.23e300), float(1.23e300)) diff --git a/Objects/longobject.c b/Objects/longobject.c index abb69b0..f14f298 100644 --- a/Objects/longobject.c +++ b/Objects/longobject.c @@ -1937,10 +1937,18 @@ long_hash(PyLongObject *v) i = -(i); } #define LONG_BIT_SHIFT (8*sizeof(long) - SHIFT) + /* The following loop produces a C long x such that (unsigned long)x + is congruent to the absolute value of v modulo ULONG_MAX. The + resulting x is nonzero if and only if v is. */ while (--i >= 0) { /* Force a native long #-bits (32 or 64) circular shift */ x = ((x << SHIFT) & ~MASK) | ((x >> LONG_BIT_SHIFT) & MASK); x += v->ob_digit[i]; + /* If the addition above overflowed (thinking of x as + unsigned), we compensate by incrementing. This preserves + the value modulo ULONG_MAX. */ + if ((unsigned long)x < v->ob_digit[i]) + x++; } #undef LONG_BIT_SHIFT x = x * sign; |