3 files changed, 7 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 1364068d6c..e4ae5afbdd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jun  9 22:38:09 2009  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* lib/cmath.rb (log10): raised exception when the given number is
+	  a negative real.
+
 Tue Jun  9 15:13:14 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* dir.c (dir_s_glob): fixed rdoc.  a patch from Joseph Pecoraro a
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 95a30c336b..1b0c65c995 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -48,7 +48,7 @@ module CMath
   end
 
   def log10(z)
-    if z.real?
+    if z.real? and z >= 0
       log10!(z)
     else
       log(z) / log!(10)
diff --git a/version.h b/version.h
index 16d42a7c0b..4ce732b555 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "1.9.1"
 #define RUBY_RELEASE_DATE "2009-05-22"
-#define RUBY_PATCHLEVEL 170
+#define RUBY_PATCHLEVEL 171
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 9
 #define RUBY_VERSION_TEENY 1