From 7783cebfdfda7d396babf2e31492dfb47737ca6d Mon Sep 17 00:00:00 2001
From: Karl Seguin <karlseguin@gmail.com>
Date: Thu, 16 Jun 2011 22:21:40 +0800
Subject: [PATCH] batch_size is taken into account when limit is 0/not set

---
 lib/mongo/cursor.rb      |  5 +++--
 test/unit/cursor_test.rb | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/lib/mongo/cursor.rb b/lib/mongo/cursor.rb
index 652d7af..4f567b2 100644
--- a/lib/mongo/cursor.rb
+++ b/lib/mongo/cursor.rb
@@ -220,12 +220,13 @@ module Mongo
     #   the server will determine the batch size.
     #
     # @return [Cursor]
-    def batch_size(size=0)
+    def batch_size(size=nil)
+      return @batch_size unless size
       check_modifiable
       if size < 0 || size == 1
         raise ArgumentError, "Invalid value for batch_size #{size}; must be 0 or > 1."
       else
-        @batch_size = size > @limit ? @limit : size
+        @batch_size = @limit != 0 && size > @limit ? @limit : size
       end
 
       self
diff --git a/test/unit/cursor_test.rb b/test/unit/cursor_test.rb
index 14f36b5..d971dad 100644
--- a/test/unit/cursor_test.rb
+++ b/test/unit/cursor_test.rb
@@ -76,6 +76,24 @@ class CursorTest < Test::Unit::TestCase
     should "cache full collection name" do
       assert_equal "testing.items", @cursor.full_collection_name
     end
+    
+    should "raise error when batch_size is 1" do
+      e = assert_raise ArgumentError do
+        @cursor.batch_size(1)
+        end
+        assert_equal "Invalid value for batch_size 1; must be 0 or > 1.", e.message
+    end
+    
+    should "use the limit for batch size when it's smaller than the specified batch_size" do
+      @cursor.limit(99)
+      @cursor.batch_size(100)
+      assert_equal 99, @cursor.batch_size
+      end
+      
+    should "use the specified batch_size" do
+      @cursor.batch_size(100)
+      assert_equal 100, @cursor.batch_size
+    end
   end
 
   context "Query fields" do