Problem URL with # on login shibboleth

[Peter Schober]

* Teresa Fasano <t.fasano at cineca.it> [2015-07-29 15:00]:
> I have a problem with an URL that contains the character "#" when I need to
> authenticate to the login page of the identity providers.
> 
> The URL is like "https://<url>=#filter...."
> 
> When the user needs to log on  to the IDP it is redirected to https://<url>,
> losing all part of the url after "#".

  "Fragments depend on the document MIME type and are evaluated by the
   client (Web browser). Clients are not supposed to send URI-fragments
   to servers when they retrieve a document"
   https://en.wikipedia.org/wiki/Fragment_identifier

So interactions of the local HTTP User Agent with any fragment
identifiers in a given resource are local/pricate to the HTTP User
Agent. The webserver (and hence the Shibboleth SP) does not know of
their use and therefor cannot put them into the RelayState the SPs
uses to keep track of the accessed location (during exchange of SAML
protocol messages with an IDP).
-peter