4 files changed, 29 insertions, 0 deletions
diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 9add810f81..23bb01d678 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Ensure that `request.filtered_parameters` is reset between calls to `process`
+    in `ActionController::TestCase`.
+
+    Fixes #13803.
+
+    *Andrew White*
+
 *   Fix `rake routes` error when `Rails::Engine` with empty routes is mounted.
 
     Fixes #13810.
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index 5ed3d2ebc1..cf11ce1a9b 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -213,6 +213,9 @@ module ActionController
       # Clear the combined params hash in case it was already referenced.
       @env.delete("action_dispatch.request.parameters")
 
+      # Clear the filter cache variables so they're not stale
+      @filtered_parameters = @filtered_env = @filtered_path = nil
+
       params = self.request_parameters.dup
       %w(controller action only_path).each do |k|
         params.delete(k)
diff --git a/actionpack/test/controller/log_subscriber_test.rb b/actionpack/test/controller/log_subscriber_test.rb
index 075347be52..18037b3d2f 100644
--- a/actionpack/test/controller/log_subscriber_test.rb
+++ b/actionpack/test/controller/log_subscriber_test.rb
@@ -137,6 +137,17 @@ class ACLogSubscriberTest < ActionController::TestCase
     assert_equal 'Parameters: {"id"=>"10"}', logs[1]
   end
 
+  def test_multiple_process_with_parameters
+    get :show, :id => '10'
+    get :show, :id => '20'
+
+    wait
+
+    assert_equal 6, logs.size
+    assert_equal 'Parameters: {"id"=>"10"}', logs[1]
+    assert_equal 'Parameters: {"id"=>"20"}', logs[4]
+  end
+
   def test_process_action_with_wrapped_parameters
     @request.env['CONTENT_TYPE'] = 'application/json'
     post :show, :id => '10', :name => 'jose'
diff --git a/actionpack/test/controller/test_case_test.rb b/actionpack/test/controller/test_case_test.rb
index de0476dbde..5ff4a383ec 100644
--- a/actionpack/test/controller/test_case_test.rb
+++ b/actionpack/test/controller/test_case_test.rb
@@ -706,6 +706,14 @@ XML
     assert @request.params[:foo].blank?
   end
 
+  def test_filtered_parameters_reset_between_requests
+    get :no_op, :foo => "bar"
+    assert_equal "bar", @request.filtered_parameters[:foo]
+
+    get :no_op, :foo => "baz"
+    assert_equal "baz", @request.filtered_parameters[:foo]
+  end
+
   def test_symbolized_path_params_reset_after_request
     get :test_params, :id => "foo"
     assert_equal "foo", @request.symbolized_path_parameters[:id]