Fix overwriting path params by query params

app/helpers/routing/pseudonymization_helper.rb

@@ -31,7 +31,7 @@ module Routing
           end
         end
 
-        generate_url(masked_params.merge(masked_query_params))
+        generate_url(masked_params.merge(params: masked_query_params))
       end
 
       private
@@ -45,7 +45,7 @@ module Routing
         elsif @request.path_parameters[:controller] == 'groups/insights'
           default_root_url + "#{Gitlab::Routing.url_helpers.group_insights_path(masked_params)}"
         else
-          Gitlab::Routing.url_helpers.url_for(masked_params.merge(masked_query_params))
+          Gitlab::Routing.url_helpers.url_for(masked_params)
         end
       end
 

spec/helpers/routing/pseudonymization_helper_spec.rb

@@ -178,6 +178,26 @@ RSpec.describe ::Routing::PseudonymizationHelper do
 
       it_behaves_like 'masked url'
     end
+
+    context 'when query string has keys with the same names as path params' do
+      let(:masked_url) { "http://localhost/dashboard/issues?action=foobar&scope=all&state=opened" }
+      let(:request) do
+        double(:Request,
+               path_parameters: {
+                controller: 'dashboard',
+                action: 'issues'
+               },
+               protocol: 'http',
+               host: 'localhost',
+               query_string: 'action=foobar&scope=all&state=opened')
+      end
+
+      before do
+        allow(helper).to receive(:request).and_return(request)
+      end
+
+      it_behaves_like 'masked url'
+    end
   end
 
   describe 'when url has no params to mask' do