diff options
| -rw-r--r-- | Objects/longobject.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/Objects/longobject.c b/Objects/longobject.c index becf1bc..9657c08 100644 --- a/Objects/longobject.c +++ b/Objects/longobject.c @@ -175,10 +175,11 @@ long PyLong_AsLong(vv) PyObject *vv; { + /* This version by Tim Peters */ register PyLongObject *v; - long x, prev; + unsigned long x, prev; int i, sign; - + if (vv == NULL || !PyLong_Check(vv)) { PyErr_BadInternalCall(); return -1; @@ -194,13 +195,22 @@ PyLong_AsLong(vv) while (--i >= 0) { prev = x; x = (x << SHIFT) + v->ob_digit[i]; - if ((x >> SHIFT) != prev) { - PyErr_SetString(PyExc_OverflowError, - "long int too long to convert"); - return -1; - } - } - return x * sign; + if ((x >> SHIFT) != prev) + goto overflow; + } + /* Haven't lost any bits, but if the sign bit is set we're in + * trouble *unless* this is the min negative number. So, + * trouble iff sign bit set && (positive || some bit set other + * than the sign bit). + */ + if ((long)x < 0 && (sign > 0 || (x << 1) != 0)) + goto overflow; + return (long)x * sign; + + overflow: + PyErr_SetString(PyExc_OverflowError, + "long int too long to convert"); + return -1; } /* Get a C long int from a long int object. |