Merged revisions 67707 via svnmerge from

mdickinson · mdickinson · commit e675f08e0333 · 2008-12-11T21:56:00.000Z
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. ........
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -87,6 +87,11 @@ Library
   support unusual filenames (such as those containing semi-colons) in
   Content-Disposition headers.
 
+Extension Modules
+-----------------
+
+- Issues #3167, #3682: Fix test_math failures for log, log10 on Solaris,
+  OpenBSD.
 
 Build
 -----
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
@@ -136,6 +136,58 @@ m_atan2(double y, double x)
 	return atan2(y, x);
 }
 
+/*
+    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.
@@ -831,11 +883,11 @@ math_log(PyObject *self, PyObject *args)
 	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;
@@ -854,7 +906,7 @@ If the base not specified, returns the natural logarithm (base e) of x.");
 static PyObject *
 math_log10(PyObject *self, PyObject *arg)
 {
-	return loghelper(arg, log10, "log10");
+	return loghelper(arg, m_log10, "log10");
 }
 
 PyDoc_STRVAR(math_log10_doc,
