When any role mapping field is empty, a deprecated function error is triggered upon a sign on attempt.

Problem/Motivation

The module uses role mapping to map Drupal user roles to Onelogin users based on their Onelogin roles. This is done by indicating in a text field for each Drupal role, the Onelogin role(s) that apply. If any of the Role mapping fields are left empty, then a deprecation error message is shown after signing in.

Error message:
Deprecated function: explode(): Passing null to parameter #2 ($string) of type string is deprecated in Drupallonelogin_ integration AuthenticationService->syncRoles() (line 254 of modules/contrib/onelogin_integration/sc/AuthenticationService.php).

Steps to reproduce

• Create multiple user roles in Drupal
• Install and configure the onelogin_integration module to work with a Onelogin Application.
• Fill in at least role mapping field, while leaving one or more empty.
• Sign out and attempt to sign in as a onelogin user
• Navigate to /admin/content and the error message should appear

Proposed resolution

Add a condition to the syncRoles() function so that empty role mapping fields are not processed.