From: Benjamin Peterson <benjamin@python.org>
Date: Tue, 17 Jun 2008 22:39:26 +0000 (+0000)
Subject: Merged revisions 64349 via svnmerge from
X-Git-Tag: v3.0b1~14
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c2c5e00d9da5cfb01e2c84043669de3d0c6fe35b;p=python

Merged revisions 64349 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r64349 | mark.dickinson | 2008-06-17 16:16:55 -0500 (Tue, 17 Jun 2008) | 4 lines

  Issue 3118: make test_math pass on Ubuntu/ia64.  exp(-745.0) was raising
  OverflowError incorrectly on this platform, presumably as a result of
  the libm setting errno = ERANGE for this call.
........
---

diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index fa607e3f1e..4c820c5848 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -82,12 +82,17 @@ is_error(double x)
 		 * should return a zero on underflow, and +- HUGE_VAL on
 		 * overflow, so testing the result for zero suffices to
 		 * distinguish the cases).
+		 *
+		 * On some platforms (Ubuntu/ia64) it seems that errno can be
+		 * set to ERANGE for subnormal results that do *not* underflow
+		 * to zero.  So to be safe, we'll ignore ERANGE whenever the
+		 * function result is less than one in absolute value.
 		 */
-		if (x)
+		if (fabs(x) < 1.0)
+			result = 0;
+		else
 			PyErr_SetString(PyExc_OverflowError,
 					"math range error");
-		else
-			result = 0;
 	}
 	else
                 /* Unexpected math error */