Bug 13568 OAI Server doesn't handle properly resumption token

Bug 13568 OAI Server doesn't handle properly resumption token

When responding to ListRecords and ListIdentifiers verbs, OAI server doesn't
return proper resumption token. At the end of a result set, OAI server
generates a resumption token even if there isn't anymore records. Consequently,
OAI harverster will send a new request, based on this invalid resumption,
token. OAI Server responds with an empty resultset, which is considered as an
invalid response by most of the harvesters.

TO TEST:

- Find in your DB, a day where a few biblio records have been created. The
  number of created biblios must inferior to OAI-PMH:MaxCount.

- Let say this day is 2014-01-09. Send an OAI-PMH request to Koha OAI Server:

  /cgi-bin/koha/oai.pl?verb=ListRecords&metadataPrefix=marcxml&from=2014-01-09&until=2014-01-09

- At the end of the result, you will see a resumption token which looks like that:

  <resumptionToken cursor="47">marcxml/47/2014-01-09/2014-01-09/</resumptionToken>

  This is wrong. No resumptiion token should be sent since there isn't anymore
  records to harvest.

- Apply the patch.

- Resend the OAI-PMH request. There is no resumption token at the end of the
  result.

- You could test also with ListIdenfiers verb in place of ListRecord.

Signed-off-by: Christophe Brocquet <christophe.brocquet@obspm.fr>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>