Issue #2487. math.ldexp(x, n) raised OverflowError when n was large and
negative; fix to return an (appropriately signed) zero instead.
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index c9eade3..a5c6f62 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -374,6 +374,24 @@
self.assertEquals(math.ldexp(NINF, -213), NINF)
self.assert_(math.isnan(math.ldexp(NAN, 0)))
+ # large second argument
+ for n in [10**5, 10L**5, 10**10, 10L**10, 10**20, 10**40]:
+ self.assertEquals(math.ldexp(INF, -n), INF)
+ self.assertEquals(math.ldexp(NINF, -n), NINF)
+ self.assertEquals(math.ldexp(1., -n), 0.)
+ self.assertEquals(math.ldexp(-1., -n), -0.)
+ self.assertEquals(math.ldexp(0., -n), 0.)
+ self.assertEquals(math.ldexp(-0., -n), -0.)
+ self.assert_(math.isnan(math.ldexp(NAN, -n)))
+
+ self.assertRaises(OverflowError, math.ldexp, 1., n)
+ self.assertRaises(OverflowError, math.ldexp, -1., n)
+ self.assertEquals(math.ldexp(0., n), 0.)
+ self.assertEquals(math.ldexp(-0., n), -0.)
+ self.assertEquals(math.ldexp(INF, n), INF)
+ self.assertEquals(math.ldexp(NINF, n), NINF)
+ self.assert_(math.isnan(math.ldexp(NAN, n)))
+
def testLog(self):
self.assertRaises(TypeError, math.log)
self.ftest('log(1/e)', math.log(1/math.e), -1)