From 544acb4deb8dd9b9f369553b4af4d0eee788e40f Mon Sep 17 00:00:00 2001
From: Yuki Nishijima <mail@yukinishijima.net>
Date: Wed, 26 Mar 2014 21:17:53 -0700
Subject: [PATCH] :disappointed_relieved:

---
 lib/kaminari/helpers/tags.rb | 21 ++++++++++++++++++---
 spec/helpers/tags_spec.rb    |  6 +++---
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/lib/kaminari/helpers/tags.rb b/lib/kaminari/helpers/tags.rb
index d802850..6fe8370 100644
--- a/lib/kaminari/helpers/tags.rb
+++ b/lib/kaminari/helpers/tags.rb
@@ -27,13 +27,28 @@ module Kaminari
       end
 
       def page_url_for(page)
-        @template.url_for @params.deep_merge(page_param(page)).merge(:only_path => true)
+        @template.url_for params_for(page).merge(:only_path => true)
       end
 
       private
 
-      def page_param(page)
-        Rack::Utils.parse_nested_query("#{@param_name}=#{page <= 1 ? nil : page}").symbolize_keys
+      def params_for(page)
+        page_params = Rack::Utils.parse_nested_query("#{@param_name}=#{page}")
+        page_params = @params.with_indifferent_access.deep_merge(page_params)
+
+        if page <= 1
+          # This converts a hash:
+          #   from: {other: "params", page: 1}
+          #     to: {other: "params"}
+          #   (when @param_name == "page")
+          #
+          #   from: {other: "params", user: {name: "yuki", page: 1}}
+          #     to: {other: "params", user: {name: "yuki"}}
+          #   (when @param_name == "user[page]")
+          @param_name.to_s.scan(/\w+/)[0..-2].inject(page_params){|h, k| h[k] }.delete($&)
+        end
+
+        page_params
       end
     end
 
diff --git a/spec/helpers/tags_spec.rb b/spec/helpers/tags_spec.rb
index 6daa83f..e3a0218 100644
--- a/spec/helpers/tags_spec.rb
+++ b/spec/helpers/tags_spec.rb
@@ -20,11 +20,11 @@ describe 'Kaminari::Helpers' do
       context "for first page" do
         subject { Tag.new(helper, :param_name => "user[page]").page_url_for(1) }
         if ActiveSupport::VERSION::STRING < "3.1.0"
-          it { should_not match /user\[page\]=1/ }
+          it { should_not match /user\[page\]/ }
           it { should match /user\[scope\]=active/ }
         else
-          it { should_not match /user%5Bpage%5D=1/ }   # match user[page]=1
-          it { should match /user%5Bscope%5D=active/ } # match user[scope]=active
+          it { should_not match /user%5Bpage%5D/ }     # not match user[page]
+          it { should match /user%5Bscope%5D=active/ } #     match user[scope]=active
         end
       end