Fix additional incompatible character encodings error when building uploaded bodies

Force all strings concatenated to the uploaded body to be binary
strings.  At this point, the force_encoding calls are unnecesary,
so they can be removed.

Fixes #311

Author: jeremyevans

History.md

@@ -1,3 +1,9 @@
+## 2.0.2 / 2022-06-28
+
+* Bug fixes:
+  * Fix additional incompatible character encodings error when building
+    uploaded bodies (Jeremy Evans #311)
+
 ## 2.0.1 / 2022-06-27
 
 * Bug fixes:

lib/rack/test/utils.rb

@@ -53,9 +53,6 @@ def build_multipart(params, _first = true, multipart = false)
 
         buffer = String.new
         build_parts(buffer, params)
-        # :nocov:
-        buffer.force_encoding(Encoding::BINARY) if Rack::Test.encoding_aware_strings?
-        # :nocov:
         buffer
       end
 
@@ -125,11 +122,10 @@ def build_primitive_part(buffer, parameter_name, value)
         buffer <<
           START_BOUNDARY <<
           "content-disposition: form-data; name=\"" <<
-          parameter_name.to_s <<
+          parameter_name.to_s.b <<
           "\"\r\n\r\n" <<
-          value.to_s <<
+          value.to_s.b <<
           "\r\n"
-        buffer.force_encoding(Encoding::BINARY)
         buffer
       end
 
@@ -138,15 +134,14 @@ def build_file_part(buffer, parameter_name, uploaded_file)
         buffer <<
           START_BOUNDARY <<
           "content-disposition: form-data; name=\"" <<
-          parameter_name.to_s <<
+          parameter_name.to_s.b <<
           "\"; filename=\"" <<
-          escape_path(uploaded_file.original_filename) <<
+          escape_path(uploaded_file.original_filename).b <<
           "\"\r\ncontent-type: " <<
-          uploaded_file.content_type.to_s <<
+          uploaded_file.content_type.to_s.b <<
           "\r\ncontent-length: " <<
-          uploaded_file.size.to_s <<
+          uploaded_file.size.to_s.b <<
           "\r\n\r\n"
-        buffer.force_encoding(Encoding::BINARY)
 
         # Handle old versions of Capybara::RackTest::Form::NilUploadedFile
         if uploaded_file.respond_to?(:set_encoding)

spec/rack/test/utils_spec.rb

@@ -183,6 +183,21 @@ def respond_to?(m, *a)
     params['people'][0]['files'][:filename].must_equal 'mb.txt'
     params['people'][0]['files'][:tempfile].read.must_equal "\u2345".b
     params['foo'].must_equal %w[1 2]
+
+    files = Rack::Test::UploadedFile.new(multipart_file('mb.txt'))
+    data  = Rack::Test::Utils.build_multipart('people' => [{ 'files' => files, 'submit-name' => "\u1234" }], 'foo' => %w[1 2])
+
+    options = {
+      'CONTENT_TYPE' => "multipart/form-data; boundary=#{Rack::Test::MULTIPART_BOUNDARY}",
+      'CONTENT_LENGTH' => data.length.to_s,
+      :input => StringIO.new(data)
+    }
+    env = Rack::MockRequest.env_for('/', options)
+    params = Rack::Multipart.parse_multipart(env)
+    params['people'][0]['submit-name'].b.must_equal  "\u1234".b
+    params['people'][0]['files'][:filename].must_equal 'mb.txt'
+    params['people'][0]['files'][:tempfile].read.must_equal "\u2345".b
+    params['foo'].must_equal %w[1 2]
   end
 
   it 'builds nested multipart bodies with an array of hashes' do