6 files changed, 24 insertions, 6 deletions
diff --git a/changelogs/unreleased/rails5-fix-47804.yml b/changelogs/unreleased/rails5-fix-47804.yml
new file mode 100644
index 00000000000..3332ed3bbaa
--- /dev/null
+++ b/changelogs/unreleased/rails5-fix-47804.yml
@@ -0,0 +1,5 @@
+---
+title: Rails5 fix stack level too deep
+merge_request: 19762
+author: Jasper Maes
+type: fixed
diff --git a/changelogs/unreleased/rails5-fix-47805.yml b/changelogs/unreleased/rails5-fix-47805.yml
new file mode 100644
index 00000000000..8bd8ad5488c
--- /dev/null
+++ b/changelogs/unreleased/rails5-fix-47805.yml
@@ -0,0 +1,6 @@
+---
+title: 'Rails5 ActionController::ParameterMissing: param is missing or the value is
+  empty: application_setting'
+merge_request: 19763
+author: Jasper Maes
+type: fixed
diff --git a/changelogs/unreleased/rails5-fix-47835.yml b/changelogs/unreleased/rails5-fix-47835.yml
new file mode 100644
index 00000000000..fe9cbf1a03a
--- /dev/null
+++ b/changelogs/unreleased/rails5-fix-47835.yml
@@ -0,0 +1,6 @@
+---
+title: Rails5 fix no implicit conversion of Hash into String. ActionController::Parameters
+  no longer returns an hash in Rails 5
+merge_request: 19792
+author: Jasper Maes
+type: fixed
diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index 2ed331d4fd2..9c53b7c3fe7 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -272,7 +272,8 @@ module API
           attrs[key] = params_hash[key]
         end
       end
-      ActionController::Parameters.new(attrs).permit!
+      permitted_attrs = ActionController::Parameters.new(attrs).permit!
+      Gitlab.rails5? ? permitted_attrs.to_h : permitted_attrs
     end
 
     def filter_by_iid(items, iid)
diff --git a/spec/controllers/admin/application_settings_controller_spec.rb b/spec/controllers/admin/application_settings_controller_spec.rb
index b4fc2aa326f..9d10d725ff3 100644
--- a/spec/controllers/admin/application_settings_controller_spec.rb
+++ b/spec/controllers/admin/application_settings_controller_spec.rb
@@ -73,7 +73,7 @@ describe Admin::ApplicationSettingsController do
     end
 
     it 'updates the restricted_visibility_levels when empty array is passed' do
-      put :update, application_setting: { restricted_visibility_levels: [] }
+      put :update, application_setting: { restricted_visibility_levels: [""] }
 
       expect(response).to redirect_to(admin_application_settings_path)
       expect(ApplicationSetting.current.restricted_visibility_levels).to be_empty
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index fbafb4a4de8..74f362fd7fc 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -512,7 +512,7 @@ describe ApplicationController do
 
     context '422 errors' do
       it 'logs a response with a string' do
-        response = spy(ActionDispatch::Response, status: 422, body: 'Hello world', content_type: 'application/json')
+        response = spy(ActionDispatch::Response, status: 422, body: 'Hello world', content_type: 'application/json', cookies: {})
         allow(controller).to receive(:response).and_return(response)
         get :index
 
@@ -521,7 +521,7 @@ describe ApplicationController do
 
       it 'logs a response with an array' do
         body = ['I want', 'my hat back']
-        response = spy(ActionDispatch::Response, status: 422, body: body, content_type: 'application/json')
+        response = spy(ActionDispatch::Response, status: 422, body: body, content_type: 'application/json', cookies: {})
         allow(controller).to receive(:response).and_return(response)
         get :index
 
@@ -529,7 +529,7 @@ describe ApplicationController do
       end
 
       it 'does not log a string with an empty body' do
-        response = spy(ActionDispatch::Response, status: 422, body: nil, content_type: 'application/json')
+        response = spy(ActionDispatch::Response, status: 422, body: nil, content_type: 'application/json', cookies: {})
         allow(controller).to receive(:response).and_return(response)
         get :index
 
@@ -537,7 +537,7 @@ describe ApplicationController do
       end
 
       it 'does not log an HTML body' do
-        response = spy(ActionDispatch::Response, status: 422, body: 'This is a test', content_type: 'application/html')
+        response = spy(ActionDispatch::Response, status: 422, body: 'This is a test', content_type: 'application/html', cookies: {})
         allow(controller).to receive(:response).and_return(response)
         get :index