Errors using <http:body> in EXPath HTTP Client 0.12.0

[StephanLehmke]

The following example doesn't work in combination with Saxon and expath-http-client-saxon-0.12.0:

<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:xs="http://www.w3.org/2001/XMLSchema"
                xmlns:http="http://expath.org/ns/http-client"
                xmlns:h="http://www.w3.org/1999/xhtml"
                exclude-result-prefixes="#all"
                version="2.0">

   <xsl:import href="http://expath.org/ns/http-client.xsl"/>

   <xsl:output indent="yes"/>

   <xsl:template name="main" match="/">
      <root>
         <!-- the request element -->
         <xsl:variable name="request" as="element(http:request)">
           <http:request method="post" href="http://127.0.0.1:8888/test">
         <http:body media-type="text/plain">foo</http:body>
       </http:request>
         </xsl:variable>
         <!-- sending the request -->
         <xsl:variable name="resp" select="http:send-request($request)"/>
         <!-- add the http:response element to the output tree -->
         <xsl:sequence select="$resp[1]"/>
      </root>
   </xsl:template>

</xsl:stylesheet>

When I run the script with

saxon -xsl:post-example.xsl -it:main
then I get the following error messages

INFO: Create a new repository with storage: File system storage in /usr/share/expath/repo
No license file found - running with licensable features disabled
2016/05/15 13:08:04:193 CEST [INFO] DefaultHttpClient - I/O exception (java.io.IOException) caught when processing request to {}->http://127.0.0.1:8888: Error serializing the body content
2016/05/15 13:08:04:195 CEST [INFO] DefaultHttpClient - Retrying request to {}->http://127.0.0.1:8888
2016/05/15 13:08:04:196 CEST [INFO] DefaultHttpClient - I/O exception (java.io.IOException) caught when processing request to {}->http://127.0.0.1:8888: Error serializing the body content
2016/05/15 13:08:04:196 CEST [INFO] DefaultHttpClient - Retrying request to {}->http://127.0.0.1:8888
2016/05/15 13:08:04:196 CEST [INFO] DefaultHttpClient - I/O exception (java.io.IOException) caught when processing request to {}->http://127.0.0.1:8888: Error serializing the body content
2016/05/15 13:08:04:196 CEST [INFO] DefaultHttpClient - Retrying request to {}->http://127.0.0.1:8888
Error on line 18 of post-example.xsl:
  Error sending the HTTP request
Error sending the HTTP request

and an invalid request is sent. The port is because I was checking the sent request with Fiddler.

With version 0.11.0 it works.