ZP-1391 Support disabling multiple IMAP auth methods, log the disabled...

ZP-1391 Support disabling multiple IMAP auth methods, log the disabled methods. Released under the Affero GNU General Public License (AGPL) version 3.

src/backend/imap/config.php

@@ -210,5 +210,6 @@ define('SYSTEM_MIME_TYPES_MAPPING', '/etc/mime.types');
 define('IMAP_MEETING_USE_CALDAV', false);
 
 // If your IMAP server allows authenticating via GSSAPI, php-imap will not fall back properly to other authentication
-// methods and you will be unable to log in. Uncomment the following line to enable use in such an environment.
+// methods and you will be unable to log in. Uncomment the following line to disable that authentication method.
+// Multiple methods can be specified as a comma-separated string.
 // define('IMAP_DISABLE_AUTHENTICATOR', 'GSSAPI');

src/backend/imap/imap.php

@@ -70,7 +70,8 @@ class BackendIMAP extends BackendDiff implements ISearchProvider {
             ZLog::Write(LOGLEVEL_WARN, sprintf("BackendIMAP(): php-mbstring module is not installed, you should install it for better encoding conversions"));
         }
         if (defined("IMAP_DISABLE_AUTHENTICATOR")) {
-	    $this->imapParams = array("DISABLE_AUTHENTICATOR" => IMAP_DISABLE_AUTHENTICATOR);
+            ZLog::Write(LOGLEVEL_INFO, sprintf("BackendIMAP(): The following authentication methods are disabled: %s", IMAP_DISABLE_AUTHENTICATOR));
+            $this->imapParams = array("DISABLE_AUTHENTICATOR" => array_map('trim' ,explode(',', IMAP_DISABLE_AUTHENTICATOR)));
         }
     }