Cannot view or delete groups with a slash in their name using provisioning API

You can create groups with all sorts of names in the webUI or with the provisioning API like:

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups -X POST -d "groupid=q?mark"
curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups -X POST -d "groupid=a%sign"
curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups -X POST -d "groupid=a/slash"

and other special characters.

You can list all groups fine with:

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups

And view individual groups with:

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups/a%sign

and to get a "?" through, you have to put the escaped value "%3F"

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups/q%3Fmark

You can delete such groups with:

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups/a%sign -X DELETE
curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups/q%3Fmark -X DELETE

The problem comes if you try with groups that have a / in their name. A literal slash is never going to work:

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups/a/slash

And an escaped slash, like this, is rejected by the server (Apache or PHP dev server):

curl http://admin:admin@localhost:8080/ocs/v2.php/cloud/groups/a%2Fslash

So you cannot manage a group like a/slash via the provisioning API. But you can manage it through webUI.

Start by reproducing the provisioning API requests in the issue for groups named a/slash, including literal and escaped slashes. Trace how the API and server handle the group name in view and DELETE requests; done means both operations work for slash-containing groups without regressing the existing special-character cases.