diff --git a/ChangeLog b/ChangeLog
index 9288a00f34..ca35e495d2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun 16 11:35:09 2011  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* lib/net/imap.rb (search_response): parses SEARCH responses from
+	  the Yahoo IMAP server correctly.  patched by Mark Nadig.  [Bug #4509]
+
 Thu Jun 16 09:12:38 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* fix for build on solaris 10.
diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index 0ddb0f346f..724bc08e3b 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -2748,8 +2748,9 @@ module Net
               break
             when T_SPACE
               shift_token
+            else
+              data.push(number)
             end
-            data.push(number)
           end
         else
           data = []
diff --git a/test/net/imap/test_imap_response_parser.rb b/test/net/imap/test_imap_response_parser.rb
index 599747dd76..ccdffd21ca 100644
--- a/test/net/imap/test_imap_response_parser.rb
+++ b/test/net/imap/test_imap_response_parser.rb
@@ -64,7 +64,6 @@ EOF
     assert_equal [:Inbox], response.data.attr
   end
 
-
   def test_resp_text_code
     parser = Net::IMAP::ResponseParser.new
     response = parser.parse(<<EOF.gsub(/\n/, "\r\n").taint)
@@ -72,4 +71,32 @@ EOF
 EOF
     assert_equal "CLOSED", response.data.code.name
   end
+
+  def test_search_response
+    parser = Net::IMAP::ResponseParser.new
+    response = parser.parse(<<EOF.gsub(/\n/, "\r\n").taint)
+* SEARCH
+EOF
+    assert_equal [], response.data
+    response = parser.parse(<<EOF.gsub(/\n/, "\r\n").taint)
+* SEARCH 1
+EOF
+    assert_equal [1], response.data
+    response = parser.parse(<<EOF.gsub(/\n/, "\r\n").taint)
+* SEARCH 1 2 3
+EOF
+    assert_equal [1, 2, 3], response.data
+  end
+
+  def test_search_response_of_yahoo
+    parser = Net::IMAP::ResponseParser.new
+    response = parser.parse(<<EOF.gsub(/\n/, "\r\n").taint)
+* SEARCH 1 
+EOF
+    assert_equal [1], response.data
+    response = parser.parse(<<EOF.gsub(/\n/, "\r\n").taint)
+* SEARCH 1 2 3 
+EOF
+    assert_equal [1, 2, 3], response.data
+  end
 end