fix file uploads with Ruby 2.0 net/http

Rewrite Faraday::CompositeReadIO because the one inherited from
multipart-post library doesn't behave well when used with
IO.copy_stream which net/http uses internally in Ruby 2.0.

lib/faraday/upload_io.rb

@@ -8,13 +8,49 @@ rescue LoadError
 end
 
 module Faraday
-  class CompositeReadIO < ::CompositeReadIO
-    attr_reader :length
+  # Similar but not compatible with ::CompositeReadIO provided by multipart-post.
+  class CompositeReadIO
+    def initialize(*parts)
+      @parts = parts.flatten
+      @ios = @parts.map { |part| part.to_io }
+      @index = 0
+    end
 
-    def initialize(parts)
-      @length = parts.inject(0) { |sum, part| sum + part.length }
-      ios = parts.map{ |part| part.to_io }
-      super(*ios)
+    def length
+      @parts.inject(0) { |sum, part| sum + part.length }
+    end
+
+    def rewind
+      @ios.each { |io| io.rewind }
+      @index = 0
+    end
+
+    # Read from IOs in order until `length` bytes have been received.
+    def read(length = nil, outbuf = nil)
+      got_result = false
+      outbuf = outbuf ? outbuf.replace("") : ""
+
+      while io = current_io
+        if result = io.read(length)
+          got_result ||= !result.nil?
+          result.force_encoding("BINARY") if result.respond_to?(:force_encoding)
+          outbuf << result
+          length -= result.length if length
+          break if length == 0
+        end
+        advance_io
+      end
+      (!got_result && length) ? nil : outbuf
+    end
+
+    private
+
+    def current_io
+      @ios[@index]
+    end
+
+    def advance_io
+      @index += 1
     end
   end
 

test/composite_read_io_test.rb

@@ -0,0 +1,107 @@
+require File.expand_path(File.join(File.dirname(__FILE__), 'helper'))
+require 'stringio'
+
+class CompositeReadIOTest < MiniTest::Unit::TestCase
+  Part = Struct.new(:to_io) do
+    def length() to_io.string.length end
+  end
+
+  def part(str)
+    Part.new StringIO.new(str)
+  end
+
+  def composite_io(*parts)
+    Faraday::CompositeReadIO.new(*parts)
+  end
+
+  def test_empty
+    io = composite_io
+    assert_equal 0, io.length
+    assert_equal "", io.read
+  end
+
+  def test_empty_returns_nil_for_limited_read
+    assert_nil composite_io.read(1)
+  end
+
+  def test_empty_parts_returns_nil_for_limited_read
+    io = composite_io(part(""), part(""))
+    assert_nil io.read(1)
+  end
+
+  def test_multipart_read_all
+    io = composite_io(part("abcd"), part("1234"))
+    assert_equal 8, io.length
+    assert_equal "abcd1234", io.read
+  end
+
+  def test_multipart_read_limited
+    io = composite_io(part("abcd"), part("1234"))
+    assert_equal "abc", io.read(3)
+    assert_equal "d12", io.read(3)
+    assert_equal "34", io.read(3)
+    assert_equal nil, io.read(3)
+    assert_equal nil, io.read(3)
+  end
+
+  def test_multipart_read_limited_size_larger_than_part
+    io = composite_io(part("abcd"), part("1234"))
+    assert_equal "abcd12", io.read(6)
+    assert_equal "34", io.read(6)
+    assert_equal nil, io.read(6)
+  end
+
+  def test_multipart_read_with_blank_parts
+    io = composite_io(part(""), part("abcd"), part(""), part("1234"), part(""))
+    assert_equal "abcd12", io.read(6)
+    assert_equal "34", io.read(6)
+    assert_equal nil, io.read(6)
+  end
+
+  def test_multipart_rewind
+    io = composite_io(part("abcd"), part("1234"))
+    assert_equal "abc", io.read(3)
+    assert_equal "d12", io.read(3)
+    io.rewind
+    assert_equal "abc", io.read(3)
+    assert_equal "d1234", io.read(5)
+    assert_equal nil, io.read(3)
+    io.rewind
+    assert_equal "ab", io.read(2)
+  end
+
+  if IO.respond_to?(:copy_stream)
+    def test_compatible_with_copy_stream
+      target_io = StringIO.new
+      io = composite_io(part("abcd"), part("1234"))
+
+      Faraday::Timer.timeout(1) do
+        IO.copy_stream(io, target_io)
+      end
+      assert_equal "abcd1234", target_io.string
+    end
+  end
+
+  unless RUBY_VERSION < '1.9'
+    def test_read_from_multibyte
+      File.open(File.dirname(__FILE__) + '/multibyte.txt') do |utf8|
+        io = composite_io(part("\x86"), Part.new(utf8))
+        assert_equal bin("\x86\xE3\x83\x95\xE3\x82\xA1\xE3\x82\xA4\xE3\x83\xAB\n"), io.read
+      end
+    end
+
+    def test_limited_from_multibyte
+      File.open(File.dirname(__FILE__) + '/multibyte.txt') do |utf8|
+        io = composite_io(part("\x86"), Part.new(utf8))
+        assert_equal bin("\x86\xE3\x83"), io.read(3)
+        assert_equal bin("\x95\xE3\x82"), io.read(3)
+        assert_equal bin("\xA1\xE3\x82\xA4\xE3\x83\xAB\n"), io.read(8)
+      end
+    end
+  end
+
+  def bin(str)
+    str.force_encoding("BINARY") if str.respond_to?(:force_encoding)
+    str
+  end
+end

test/multibyte.txt

@@ -0,0 +1 @@
+ファイル