[Python-checkins] r67709 - in python/branches/release26-maint: Misc/NEWS Modules/mathmodule.c

[mark.dickinson]

Author: mark.dickinson
Date: Thu Dec 11 22:59:08 2008
New Revision: 67709

Log:
Merged revisions 67707 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r67707 | mark.dickinson | 2008-12-11 19:28:08 +0000 (Thu, 11 Dec 2008) | 5 lines
  
  Issues #3167, #3682: tests for math.log and math.log10 were failing on
  Solaris and OpenBSD.  Fix this by handling special values and domain
  errors directly in mathmodule.c, passing only positive nonspecial floats
  to the system log/log10.
........


Modified:
   python/branches/release26-maint/   (props changed)
   python/branches/release26-maint/Misc/NEWS
   python/branches/release26-maint/Modules/mathmodule.c

Modified: python/branches/release26-maint/Misc/NEWS
==============================================================================
--- python/branches/release26-maint/Misc/NEWS	(original)
+++ python/branches/release26-maint/Misc/NEWS	Thu Dec 11 22:59:08 2008
@@ -155,6 +155,9 @@
 Extension Modules
 -----------------
 
+- Issues #3167, #3682: Fix test_math failures for log, log10 on Solaris,
+  OpenBSD.
+
 - Issue #4365: Add crtassem.h constants to the msvcrt module.
 
 - Issue #4396: The parser module now correctly validates the with statement.

Modified: python/branches/release26-maint/Modules/mathmodule.c
==============================================================================
--- python/branches/release26-maint/Modules/mathmodule.c	(original)
+++ python/branches/release26-maint/Modules/mathmodule.c	Thu Dec 11 22:59:08 2008
@@ -137,6 +137,58 @@
 }
 
 /*
+    Various platforms (Solaris, OpenBSD) do nonstandard things for log(0),
+    log(-ve), log(NaN).  Here are wrappers for log and log10 that deal with
+    special values directly, passing positive non-special values through to
+    the system log/log10.
+ */
+
+static double
+m_log(double x)
+{
+	if (Py_IS_FINITE(x)) {
+		if (x > 0.0)
+			return log(x);
+		errno = EDOM;
+		if (x == 0.0)
+			return -Py_HUGE_VAL; /* log(0) = -inf */
+		else
+			return Py_NAN; /* log(-ve) = nan */
+	}
+	else if (Py_IS_NAN(x))
+		return x; /* log(nan) = nan */
+	else if (x > 0.0)
+		return x; /* log(inf) = inf */
+	else {
+		errno = EDOM;
+		return Py_NAN; /* log(-inf) = nan */
+	}
+}
+
+static double
+m_log10(double x)
+{
+	if (Py_IS_FINITE(x)) {
+		if (x > 0.0)
+			return log10(x);
+		errno = EDOM;
+		if (x == 0.0)
+			return -Py_HUGE_VAL; /* log10(0) = -inf */
+		else
+			return Py_NAN; /* log10(-ve) = nan */
+	}
+	else if (Py_IS_NAN(x))
+		return x; /* log10(nan) = nan */
+	else if (x > 0.0)
+		return x; /* log10(inf) = inf */
+	else {
+		errno = EDOM;
+		return Py_NAN; /* log10(-inf) = nan */
+	}
+}
+
+
+/*
    math_1 is used to wrap a libm function f that takes a double
    arguments and returns a double.
 
@@ -758,11 +810,11 @@
 	if (!PyArg_UnpackTuple(args, "log", 1, 2, &arg, &base))
 		return NULL;
 
-	num = loghelper(arg, log, "log");
+	num = loghelper(arg, m_log, "log");
 	if (num == NULL || base == NULL)
 		return num;
 
-	den = loghelper(base, log, "log");
+	den = loghelper(base, m_log, "log");
 	if (den == NULL) {
 		Py_DECREF(num);
 		return NULL;
@@ -781,7 +833,7 @@
 static PyObject *
 math_log10(PyObject *self, PyObject *arg)
 {
-	return loghelper(arg, log10, "log10");
+	return loghelper(arg, m_log10, "log10");
 }
 
 PyDoc_STRVAR(math_log10_doc,