Issue #11144: Fix corner cases where float-to-int conversion unnecessarily returned a long.
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 77b1005..63b7c17 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -1035,14 +1035,17 @@
* happens if the double is too big to fit in a long. Some rare
* systems raise an exception then (RISCOS was mentioned as one,
* and someone using a non-default option on Sun also bumped into
- * that). Note that checking for >= and <= LONG_{MIN,MAX} would
- * still be vulnerable: if a long has more bits of precision than
- * a double, casting MIN/MAX to double may yield an approximation,
- * and if that's rounded up, then, e.g., wholepart=LONG_MAX+1 would
- * yield true from the C expression wholepart<=LONG_MAX, despite
- * that wholepart is actually greater than LONG_MAX.
+ * that). Note that checking for <= LONG_MAX is unsafe: if a long
+ * has more bits of precision than a double, casting LONG_MAX to
+ * double may yield an approximation, and if that's rounded up,
+ * then, e.g., wholepart=LONG_MAX+1 would yield true from the C
+ * expression wholepart<=LONG_MAX, despite that wholepart is
+ * actually greater than LONG_MAX. However, assuming a two's complement
+ * machine with no trap representation, LONG_MIN will be a power of 2 (and
+ * hence exactly representable as a double), and LONG_MAX = -1-LONG_MIN, so
+ * the comparisons with (double)LONG_MIN below should be safe.
*/
- if (LONG_MIN < wholepart && wholepart < LONG_MAX) {
+ if ((double)LONG_MIN <= wholepart && wholepart < -(double)LONG_MIN) {
const long aslong = (long)wholepart;
return PyInt_FromLong(aslong);
}