Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

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  r62914 | skip.montanaro | 2008-05-08 20:45:00 -0400 (Thu, 08 May 2008) | 4 lines

  Add an example about using NamedTemporaryFile() to replace mktemp().  I'm
  unclear whether the verbatim text should have been indented or by how much.
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  r62915 | benjamin.peterson | 2008-05-08 20:50:40 -0400 (Thu, 08 May 2008) | 2 lines

  reindent example
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  r62927 | georg.brandl | 2008-05-09 02:09:25 -0400 (Fri, 09 May 2008) | 2 lines

  #2788: add .hgignore file.
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  r62928 | georg.brandl | 2008-05-09 02:10:43 -0400 (Fri, 09 May 2008) | 2 lines

  #2781: fix function name.
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  r62929 | georg.brandl | 2008-05-09 02:18:27 -0400 (Fri, 09 May 2008) | 2 lines

  Add a sentence to basicConfig() that is in the docstring.
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  r62930 | georg.brandl | 2008-05-09 02:26:54 -0400 (Fri, 09 May 2008) | 2 lines

  Add another link to colorsys docs.
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  r62931 | georg.brandl | 2008-05-09 02:36:07 -0400 (Fri, 09 May 2008) | 2 lines

  Add Kodos as a re reference.
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  r62932 | georg.brandl | 2008-05-09 02:39:58 -0400 (Fri, 09 May 2008) | 2 lines

  Add a note about using reload().
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  r62933 | andrew.kuchling | 2008-05-09 07:46:05 -0400 (Fri, 09 May 2008) | 3 lines

  Update planned release date.
  Uncomment PEP 370 section.
  Add some module items
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  r62934 | christian.heimes | 2008-05-09 08:19:09 -0400 (Fri, 09 May 2008) | 1 line

  Add --user option to build_ext
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  r62948 | mark.dickinson | 2008-05-09 13:54:23 -0400 (Fri, 09 May 2008) | 3 lines

  Issue #2487.  math.ldexp(x, n) raised OverflowError when n was large and
  negative; fix to return an (appropriately signed) zero instead.
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  r62949 | martin.v.loewis | 2008-05-09 14:21:55 -0400 (Fri, 09 May 2008) | 1 line

  Use the CHM file name that Sphinx assigns.
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1 files changed, 54 insertions, 12 deletions

diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index fffb630..d7aba68 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -425,23 +425,65 @@ static PyObject *
 math_ldexp(PyObject *self, PyObject *args)
 {
 	double x, r;
-	int exp;
-	if (! PyArg_ParseTuple(args, "di:ldexp", &x, &exp))
+	PyObject *oexp;
+	long exp;
+	if (! PyArg_ParseTuple(args, "dO:ldexp", &x, &oexp))
 		return NULL;
-	errno = 0;
-	PyFPE_START_PROTECT("in math_ldexp", return 0)
-	r = ldexp(x, exp);
-	PyFPE_END_PROTECT(r)
-	if (Py_IS_FINITE(x) && Py_IS_INFINITY(r))
+
+	if (PyLong_Check(oexp)) {
+		/* on overflow, replace exponent with either LONG_MAX
+		   or LONG_MIN, depending on the sign. */
+		exp = PyLong_AsLong(oexp);
+		if (exp == -1 && PyErr_Occurred()) {
+			if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
+				if (Py_SIZE(oexp) < 0) {
+					exp = LONG_MIN;
+				}
+				else {
+					exp = LONG_MAX;
+				}
+				PyErr_Clear();
+			}
+			else {
+				/* propagate any unexpected exception */
+				return NULL;
+			}
+		}
+	}
+	else if (PyLong_Check(oexp)) {
+		exp = PyLong_AS_LONG(oexp);
+	}
+	else {
+		PyErr_SetString(PyExc_TypeError,
+				"Expected an int or long as second argument "
+				"to ldexp.");
+		return NULL;
+	}
+
+	if (x == 0. || !Py_IS_FINITE(x)) {
+		/* NaNs, zeros and infinities are returned unchanged */
+		r = x;
+		errno = 0;
+	} else if (exp > INT_MAX) {
+		/* overflow */
+		r = copysign(Py_HUGE_VAL, x);
 		errno = ERANGE;
-	/* Windows MSVC8 sets errno = EDOM on ldexp(NaN, i);
-	   we unset it to avoid raising a ValueError here. */
-	if (errno == EDOM)
+	} else if (exp < INT_MIN) {
+		/* underflow to +-0 */
+		r = copysign(0., x);
 		errno = 0;
+	} else {
+		errno = 0;
+		PyFPE_START_PROTECT("in math_ldexp", return 0);
+		r = ldexp(x, (int)exp);
+		PyFPE_END_PROTECT(r);
+		if (Py_IS_INFINITY(r))
+			errno = ERANGE;
+	}
+
 	if (errno && is_error(r))
 		return NULL;
-	else
-		return PyFloat_FromDouble(r);
+	return PyFloat_FromDouble(r);
 }
 
 PyDoc_STRVAR(math_ldexp_doc,