Ruby 1.9 compat: fix JSON decoding to work properly with multibyte values

[#1969 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activesupport/lib/active_support/json/decoding.rb

@@ -46,10 +46,11 @@ module ActiveSupport
             json.gsub(/\\\//, '/')
           else
             left_pos  = [-1].push(*marks)
-            right_pos = marks << json.length
+            right_pos = marks << scanner.pos + scanner.rest_size
             output    = []
             left_pos.each_with_index do |left, i|
-              output << json[left.succ..right_pos[i]]
+              scanner.pos = left.succ
+              output << scanner.peek(right_pos[i] - scanner.pos + 1)
             end
             output = output * " "
             

activesupport/test/json/decoding_test.rb

@@ -1,3 +1,4 @@
+# encoding: UTF-8
 require 'abstract_unit'
 
 class TestJSONDecoding < Test::Unit::TestCase
@@ -10,6 +11,8 @@ class TestJSONDecoding < Test::Unit::TestCase
     %({"returnTo":[1,"\\"a\\",", "b"]})        => {"returnTo" => [1, "\"a\",", "b"]},
     %({a: "'", "b": "5,000"})                  => {"a" => "'", "b" => "5,000"},
     %({a: "a's, b's and c's", "b": "5,000"})   => {"a" => "a's, b's and c's", "b" => "5,000"},
+    # multibyte
+    %({"matzue": "松江", "asakusa": "浅草"}) => {"matzue" => "松江", "asakusa" => "浅草"},
     %({a: "2007-01-01"})                       => {'a' => Date.new(2007, 1, 1)}, 
     %({a: "2007-01-01 01:12:34 Z"})            => {'a' => Time.utc(2007, 1, 1, 1, 12, 34)}, 
     # no time zone