* lib/rexml/source.rb (REXML::Source::encoding): should not

  convert the body twice.  [ruby-core:08828]

* lib/rexml/encoding.rb (REXML::Encoding::encoding):
  Encoding#encoding= to return boolean value to tell if the body
  is really converted or not.

* lib/rexml/encoding.rb (REXML::Encoding::encoding): Specific
  conversion library (e.g. rexml/encodings/UTF-16.rb) to have
  higher preceding.

* lib/rexml/encodings/UTF-16.rb (REXML::Encoding::decode_utf16):
  UTF-16#decode_utf16 should work strings without BOM.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@10910 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 19 insertions, 16 deletions

diff --git a/lib/rexml/encoding.rb b/lib/rexml/encoding.rb
index 8acc8a3698..51742faf44 100644
--- a/lib/rexml/encoding.rb
+++ b/lib/rexml/encoding.rb
@@ -24,21 +24,22 @@ module REXML
       old_verbosity = $VERBOSE
       begin
         $VERBOSE = false
-        return if defined? @encoding and enc == @encoding
+				enc = enc.nil? ? nil : enc.upcase
+        return false if defined? @encoding and enc == @encoding
         if enc and enc != UTF_8
-          @encoding = enc.upcase
-          begin
-            require 'rexml/encodings/ICONV.rb'
-            Encoding.apply(self, "ICONV")
-          rescue LoadError, Exception => err
-            raise ArgumentError, "Bad encoding name #@encoding" unless @encoding =~ /^[\w-]+$/
-            @encoding.untaint 
-            enc_file = File.join( "rexml", "encodings", "#@encoding.rb" )
-            begin
-              require enc_file
-              Encoding.apply(self, @encoding)
-            rescue LoadError
-              puts $!.message
+					@encoding = enc
+					raise ArgumentError, "Bad encoding name #@encoding" unless @encoding =~ /^[\w-]+$/
+					@encoding.untaint 
+					enc_file = File.join( "rexml", "encodings", "#@encoding.rb" )
+					begin
+						require enc_file
+						Encoding.apply(self, @encoding)
+          rescue LoadError, Exception
+						begin
+							require 'rexml/encodings/ICONV.rb'
+							Encoding.apply(self, "ICONV")
+            rescue LoadError => err
+              puts err.message
               raise ArgumentError, "No decoder found for encoding #@encoding.  Please install iconv."
             end
           end
@@ -50,6 +51,7 @@ module REXML
       ensure
         $VERBOSE = old_verbosity
       end
+			true
     end
 
     def check_encoding str
diff --git a/lib/rexml/encodings/UTF-16.rb b/lib/rexml/encodings/UTF-16.rb
index 972169755e..792adfd44d 100644
--- a/lib/rexml/encodings/UTF-16.rb
+++ b/lib/rexml/encodings/UTF-16.rb
@@ -16,9 +16,10 @@ module REXML
     end
 
     def decode_utf16(str)
+      str = str[2..-1] if /^\376\377/ =~ str
       array_enc=str.unpack('C*')
       array_utf8 = []
-      2.step(array_enc.size-1, 2){|i| 
+      0.step(array_enc.size-1, 2){|i| 
         array_utf8 << (array_enc.at(i+1) + array_enc.at(i)*0x100)
       }
       array_utf8.pack('U*')
diff --git a/lib/rexml/source.rb b/lib/rexml/source.rb
index c51f504811..3b6e813baf 100644
--- a/lib/rexml/source.rb
+++ b/lib/rexml/source.rb
@@ -44,7 +44,7 @@ module REXML
 		# Inherited from Encoding
 		# Overridden to support optimized en/decoding
 		def encoding=(enc)
-			super
+			return unless super
 			@line_break = encode( '>' )
 			if enc != UTF_8
 				@buffer = decode(@buffer)