federation sharing does not work when remote server has capital letters in URL path

Steps to reproduce

have two instances of oC installed one should have capital case letters in the URL path e.g. http://localhost/owncloud-10.2.0/rc1 and http://localhost/owncloud-10.2.0/RC1_b
try to share federation shares from rc1 to RC1_b

Expected behaviour

sharing works

Actual behaviour

message saying: Sharing Documents failed, could not find admin@http://localhost/owncloud-10.2.0/rc1_b, maybe the server is currently unreachable.

it tries to access rc1_b but the path is RC1_b

Server configuration

Operating system: Ubuntu 18.04 Web server: Apache2 Database: SQlite PHP version: 7.2 ownCloud version: (see ownCloud admin page) 10.2.0.1 Updated from an older ownCloud or fresh install: fresh Where did you install ownCloud from: https://download.owncloud.org/community/testing/owncloud-10.2.0RC1.tar.bz2

The content of config/config.php: rc1

{
    "system": {
        "instanceid": "oczulqjvk0g8",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "172.17.0.1"
        ],
        "datadirectory": "\/home\/artur\/www\/owncloud-10.2.0\/rc1\/data",
        "overwrite.cli.url": "http:\/\/localhost\/owncloud-10.2.0\/rc1",
        "dbtype": "sqlite3",
        "version": "10.2.0.1",
        "logtimezone": "UTC",
        "apps_paths": [
            {
                "path": "\/home\/artur\/www\/owncloud-10.2.0\/rc1\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/home\/artur\/www\/owncloud-10.2.0\/rc1\/apps-external",
                "url": "\/apps-external",
                "writable": true
            }
        ],
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "sharing.federation.allowHttpFallback": true
    }
}

RC1_b

{
    "system": {
        "instanceid": "oc5adqzniycz",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "172.17.0.1"
        ],
        "datadirectory": "\/home\/artur\/www\/owncloud-10.2.0\/RC1_b\/data",
        "overwrite.cli.url": "http:\/\/localhost\/owncloud-10.2.0\/RC1_b",
        "dbtype": "sqlite3",
        "version": "10.2.0.1",
        "logtimezone": "UTC",
        "apps_paths": [
            {
                "path": "\/home\/artur\/www\/owncloud-10.2.0\/RC1_b\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/home\/artur\/www\/owncloud-10.2.0\/RC1_b\/apps-external",
                "url": "\/apps-external",
                "writable": true
            }
        ],
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "sharing.federation.allowHttpFallback": true
    }
}

installed apps

Enabled:
  - comments: 0.3.0
  - configreport: 0.2.0
  - dav: 0.4.0
  - federatedfilesharing: 0.4.0
  - federation: 0.1.0
  - files: 1.5.2
  - files_external: 0.7.1
  - files_sharing: 0.11.0
  - files_trashbin: 0.9.1
  - files_versions: 1.3.0
  - files_videoplayer: 0.10.1
  - firstrunwizard: 1.2.0
  - market: 0.4.0
  - notifications: 0.5.0
  - provisioning_api: 0.5.0
  - systemtags: 0.3.0
  - updatenotification: 0.2.1
Disabled:
  - encryption
  - external
  - user_external

Are you using external storage, if yes which one: local/smb/sftp/... no Are you using encryption: yes/no no Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/... no

Client configuration

Browser: Firefox / Chrome Operating system: Ubuntu 18.04

Logs

ownCloud log (data/owncloud.log)

{"reqId":"byg4JYsIbtOLASSDu4Bd","level":3,"time":"2019-04-17T11:19:16+00:00","remoteAddr":"::1","user":"admin","app":"no app in context","method":"POST","url":"\/owncloud-10.2.0\/rc1\/ocs\/v2.php\/apps\/files_sharing\/api\/v1\/shares?format=json","message":"Failed to notify remote server of federated share, removing share (Sharing Documents failed, could not find admin@http:\/\/localhost\/owncloud-10.2.0\/rc1_b, maybe the server is currently unreachable.)"}

owncloud / core