merges r30543 from trunk into ruby_1_9_2.

--
* lib/net/imap.rb: use bytesize for binary strings.
  patched by Yoshimasa Niwa. [ruby-core:34222]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@30576 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/net/imap.rb

@@ -1237,7 +1237,7 @@ module Net
     end
 
     def send_literal(str)
-      put_string("{" + str.length.to_s + "}" + CRLF)
+      put_string("{" + str.bytesize.to_s + "}" + CRLF)
       @continuation_request_arrival.wait
       raise @exception if @exception
       put_string(str)
@@ -2571,7 +2571,7 @@ module Net
           return '""'
         when /[\x80-\xff\r\n]/n
           # literal
-          return "{" + str.length.to_s + "}" + CRLF + str
+          return "{" + str.bytesize.to_s + "}" + CRLF + str
         when /[(){ \x00-\x1f\x7f%*"\\]/n
           # quoted string
           return '"' + str.gsub(/["\\]/n, "\\\\\\&") + '"'