Preserve query parameters in pagination links from POST request

lib/will_paginate/view_helpers/action_view.rb

@@ -119,8 +119,12 @@ def url(page)
       end
 
       def merge_get_params(url_params)
-        if @template.respond_to? :request and @template.request and @template.request.get?
-          symbolized_update(url_params, @template.params, GET_PARAMS_BLACKLIST)
+        if @template.respond_to?(:request) and @template.request
+          if @template.request.get?
+            symbolized_update(url_params, @template.params, GET_PARAMS_BLACKLIST)
+          elsif @template.request.respond_to?(:query_parameters)
+            symbolized_update(url_params, @template.request.query_parameters, GET_PARAMS_BLACKLIST)
+          end
         end
         url_params
       end

spec/view_helpers/action_view_spec.rb

@@ -220,11 +220,13 @@ def renderer.gap() '<span class="my-gap">~~</span>' end
     assert_no_links_match /p0wned/
   end
 
-  it "should not preserve parameters on POST" do
+  it "should only preserve query parameters on POST" do
     request.post
     request.params :foo => 'bar'
+    request.query_parameters = { :hello => 'world' }
     paginate
     assert_no_links_match /foo=bar/
+    assert_links_match /hello=world/
   end
 
   it "should add additional parameters to links" do
@@ -465,6 +467,18 @@ def params(more = nil)
     @params.update(more) if more
     ActionController::Parameters.new(@params)
   end
+
+  def query_parameters
+    if get?
+      params
+    else
+      ActionController::Parameters.new(@query_parameters)
+    end
+  end
+
+  def query_parameters=(more)
+    @query_parameters = more.with_indifferent_access
+  end
 
   def host_with_port
     'example.com'