Fix Interoperability with Zlib::GzipReader

lib/json/common.rb

@@ -699,10 +699,10 @@ def load(source, proc = nil, allow_blank: true, **options)
     unless source.is_a?(String)
       if source.respond_to? :to_str
         source = source.to_str
+      elsif source.respond_to? :read
+        source = source.read
       elsif source.respond_to? :to_io
         source = source.to_io.read
-      elsif source.respond_to?(:read)
-        source = source.read
       end
     end
 

test/json/json_common_interface_test.rb

@@ -122,15 +122,25 @@ def o.to_s
 
   def test_load
     assert_equal @hash, JSON.load(@json)
+    assert_equal nil, JSON.load(nil)
+    assert_equal nil, JSON.load('')
+
     tempfile = Tempfile.open('@json')
     tempfile.write @json
     tempfile.rewind
     assert_equal @hash, JSON.load(tempfile)
+
     stringio = StringIO.new(@json)
     stringio.rewind
     assert_equal @hash, JSON.load(stringio)
-    assert_equal nil, JSON.load(nil)
-    assert_equal nil, JSON.load('')
+
+    tempfile = Tempfile.open('@json.gzip')
+    gzw = Zlib::GzipWriter.new(tempfile)
+    gzw.write(@json)
+    gzw.close
+    tempfile.open
+    gzr = Zlib::GzipReader.new(tempfile)
+    assert_equal @hash, JSON.load(gzr)
   ensure
     tempfile.close!
   end

test/json/test_helper.rb

@@ -31,6 +31,7 @@
 require 'test/unit'
 require 'stringio'
 require 'tempfile'
+require 'zlib'
 begin
   require 'bigdecimal'
 rescue LoadError