title: Deploying war file using xml on jetty9
body: <p>I am trying to deploy a war file on jetty9, it works fine if I drop it into webapps folder but I want to deploy it using a xml file.</p>
  
  <p>Here's the exception I am getting: </p>
  
  <pre><code>2015-10-22 17:36:39.593:WARN:oejw.WebAppContext:main: Failed startup of context o.e.j.w.WebAppContext@61a485d2{/myapp,file:///tmp/jetty-openbd.war-_myapp-any-1881803922382581907.dir/webapp/,null}{/opt/openbd.org/openbd.war}
  java.lang.NullPointerException
      at org.eclipse.jetty.webapp.MetaInfConfiguration.preConfigure(MetaInfConfiguration.java:77)
      at org.eclipse.jetty.webapp.WebAppContext.preConfigure(WebAppContext.java:474)
      at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:510)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at org.eclipse.jetty.xml.XmlConfiguration$1.run(XmlConfiguration.java:1510)
      at java.security.AccessController.doPrivileged(Native Method)
      at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1435)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:497)
      at org.eclipse.jetty.start.Main.invokeMain(Main.java:214)
      at org.eclipse.jetty.start.Main.start(Main.java:457)
      at org.eclipse.jetty.start.Main.main(Main.java:75)
  </code></pre>
  
  <p>and my xml :</p>
  
  <pre><code>&lt;?xml version="1.0"  encoding="ISO-8859-1"?&gt;
  &lt;!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN"
     "http://www.eclipse.org/jetty/configure_9_0.dtd"&gt;
  
  &lt;Configure class="org.eclipse.jetty.webapp.WebAppContext"&gt;
    &lt;Set name="contextPath"&gt;/myapp&lt;/Set&gt;
    &lt;Set name="war"&gt;/opt/openbd.org/openbd.war&lt;/Set&gt;
  &lt;/Configure&gt;
  </code></pre>
  
  <p>I tried with <code>&lt;Set name="extractWAR"&gt;true&lt;/Set&gt;</code> with no luck.</p>
  
  <p>I also used <code>--debug</code> which didn't provide any clue..</p>
  
  <p>What am I doing wrong? Jetty version: jetty-9.3.3.v20150827</p>