2 files changed, 5 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index ef37534751..aeaf9c2b68 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Jun  7 22:44:20 2009  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* lib/cmath.rb (log): avoided redundant expression.
+
 Fri Jun  5 07:12:32 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* lib/mkmf.rb (#link_command): should dup CONFTEST_C which is
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 95a30c336b..5b261ed6a8 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -38,8 +38,7 @@ module CMath
     if z.real? and z >= 0 and (b.nil? or b >= 0)
       log!(*args)
     else
-      r, theta = z.polar
-      a = Complex(log!(r.abs), theta)
+      a = Complex(log!(z.abs), z.arg)
       if b
 	a /= log(b)
       end