title: mod_auth_mellon environment variables are null
body: <p>I am using mod_auth_mellon on Apache for external authentication using SAML with an ADFS as IDP.  I'm getting a Session Cookie an the Authentification is working but I do not get the attributes sent by the IDP. </p>
  
  <p>I read in the answer in another topic (<a href="https://stackoverflow.com/questions/32709589/mod-auth-mellon-not-populating-environment-variables/">mod_auth_mellon not populating environment variables</a>) that the attributes have to be written in the RequestHeader and thats what I'm doing.</p>
  
  <p>My mellon configuration is as follows:</p>
  
  <pre><code>&lt;Location / &gt;
      MellonEnable info
      MellonSessionDump On
      MellonSamlResponseDump On
  
      MellonEndpointPath /mellon             
      MellonSPMetadataFile /etc/apache2/saml2/metadata.xml
      MellonSPPrivateKeyFile /etc/apache2/saml2/metadata.key
      MellonSPCertFile /etc/apache2/saml2/metadata.cert
      MellonIdPMetadataFile /etc/apache2/saml2/FederationMetadata.xml
  
  
      MellonSetEnv "MELLON_SESSION" "MELLON_SESSION"
      MellonSetEnv "MELLON_SAML_RESPONSE" "MELLON_SAML_RESPONSE"
  
      RequestHeader set Mellon-Session "%{MELLON_SESSION}e"
      RequestHeader set Mellon-SAML-Response %{MELLON_SAML_RESPONSE}e
  
     MellonSetEnvNoPrefix "MELLON_uid" "uid"
     MellonSetEnvNoPrefix "MELLON_NameID" "NameID"
  
      RequestHeader set Mellon-UID %{MELLON_uid}e
      RequestHeader set Mellon-NameID "%{MELLON_NAME_ID}e"
  &lt;/Location&gt;
  
  # This is a location that will trigger authentication when requested.
  &lt;Location /adfshandler &gt;
      AuthType Mellon
      MellonEnable auth
      Require valid-user
  &lt;/Location&gt;
  </code></pre>
  
  <p>I can see the set Atributes in the Header and I have values for all of them except uid, uid is null. Do I have to specify the requestet attributes somewhere? Or is it the wrong name?</p>