From 19e15f7b029b3c3c5e9eeed948a37e2316ed5975 Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Thu, 18 Dec 2008 19:30:35 -0800
Subject: [PATCH] MogileFS::Mysql: list_keys returns nil if nothing was found

This is to be compatible with MogileFS::MogileFS
---
 lib/mogilefs/mysql.rb | 3 ++-
 test/test_mysql.rb    | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/mogilefs/mysql.rb b/lib/mogilefs/mysql.rb
index c8a35e0..67432ed 100644
--- a/lib/mogilefs/mysql.rb
+++ b/lib/mogilefs/mysql.rb
@@ -60,7 +60,8 @@ class MogileFS::Mysql
       yield(dkey, length, devcount) if block_given?
       keys << dkey
     end
-    [ keys, (keys.last || '') ]
+
+    keys.empty? ? nil : [ keys, (keys.last || '') ]
   end
 
   ##
diff --git a/test/test_mysql.rb b/test/test_mysql.rb
index 822916f..872f05f 100644
--- a/test/test_mysql.rb
+++ b/test/test_mysql.rb
@@ -119,6 +119,11 @@ class TestMogileFS__Mysql < Test::Unit::TestCase
     assert_equal expect_full, full
   end
 
+  def test_list_keys_empty
+    @my.expect << []
+    assert_nil @mg.list_keys
+  end
+
   def test_size
     @my.expect << [ [ '123' ] ]
     assert_equal 123, @mg.size('foo')
-- 
2.11.4.GIT