3 files changed, 35 insertions, 3 deletions
diff --git a/activestorage/test/controllers/disk_controller_test.rb b/activestorage/test/controllers/disk_controller_test.rb
index eacb9bfc11..940dbf5918 100644
--- a/activestorage/test/controllers/disk_controller_test.rb
+++ b/activestorage/test/controllers/disk_controller_test.rb
@@ -8,7 +8,7 @@ class ActiveStorage::DiskControllerTest < ActionDispatch::IntegrationTest
     blob = create_blob
 
     get blob.service_url
-    assert_equal "inline; filename=\"hello.txt\"", @response.headers["Content-Disposition"]
+    assert_equal "inline; filename=\"hello.txt\"; filename*=UTF-8''hello.txt", @response.headers["Content-Disposition"]
     assert_equal "text/plain", @response.headers["Content-Type"]
   end
 
@@ -16,7 +16,7 @@ class ActiveStorage::DiskControllerTest < ActionDispatch::IntegrationTest
     blob = create_blob
 
     get blob.service_url(disposition: :attachment)
-    assert_equal "attachment; filename=\"hello.txt\"", @response.headers["Content-Disposition"]
+    assert_equal "attachment; filename=\"hello.txt\"; filename*=UTF-8''hello.txt", @response.headers["Content-Disposition"]
     assert_equal "text/plain", @response.headers["Content-Type"]
   end
 
diff --git a/activestorage/test/models/blob_test.rb b/activestorage/test/models/blob_test.rb
index 03bf72c0de..6e815997ba 100644
--- a/activestorage/test/models/blob_test.rb
+++ b/activestorage/test/models/blob_test.rb
@@ -50,7 +50,7 @@ class ActiveStorage::BlobTest < ActiveSupport::TestCase
 
   private
     def expected_url_for(blob, disposition: :inline)
-      query_string = { content_type: blob.content_type, disposition: "#{disposition}; filename=\"#{blob.filename}\"" }.to_param
+      query_string = { content_type: blob.content_type, disposition: "#{disposition}; #{blob.filename.parameters}" }.to_param
       "/rails/active_storage/disk/#{ActiveStorage.verifier.generate(blob.key, expires_in: 5.minutes, purpose: :blob_key)}/#{blob.filename}?#{query_string}"
     end
 end
diff --git a/activestorage/test/models/filename/parameters_test.rb b/activestorage/test/models/filename/parameters_test.rb
new file mode 100644
index 0000000000..431be00639
--- /dev/null
+++ b/activestorage/test/models/filename/parameters_test.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class ActiveStorage::Filename::ParametersTest < ActiveSupport::TestCase
+  test "parameterizing a Latin filename" do
+    filename = ActiveStorage::Filename.new("racecar.jpg")
+
+    assert_equal %(filename="racecar.jpg"), filename.parameters.ascii
+    assert_equal "filename*=UTF-8''racecar.jpg", filename.parameters.utf8
+    assert_equal "#{filename.parameters.ascii}; #{filename.parameters.utf8}", filename.parameters.combined
+    assert_equal filename.parameters.combined, filename.parameters.to_s
+  end
+
+  test "parameterizing a Latin filename with accented characters" do
+    filename = ActiveStorage::Filename.new("råcëçâr.jpg")
+
+    assert_equal %(filename="racecar.jpg"), filename.parameters.ascii
+    assert_equal "filename*=UTF-8''r%C3%A5c%C3%AB%C3%A7%C3%A2r.jpg", filename.parameters.utf8
+    assert_equal "#{filename.parameters.ascii}; #{filename.parameters.utf8}", filename.parameters.combined
+    assert_equal filename.parameters.combined, filename.parameters.to_s
+  end
+
+  test "parameterizing a non-Latin filename" do
+    filename = ActiveStorage::Filename.new("автомобиль.jpg")
+
+    assert_equal %(filename="%3F%3F%3F%3F%3F%3F%3F%3F%3F%3F.jpg"), filename.parameters.ascii
+    assert_equal "filename*=UTF-8''%D0%B0%D0%B2%D1%82%D0%BE%D0%BC%D0%BE%D0%B1%D0%B8%D0%BB%D1%8C.jpg", filename.parameters.utf8
+    assert_equal "#{filename.parameters.ascii}; #{filename.parameters.utf8}", filename.parameters.combined
+    assert_equal filename.parameters.combined, filename.parameters.to_s
+  end
+end