Exclude LDAP backend from global user searches

triggered by itself.

apps/user_ldap/lib/access.php

@@ -281,8 +281,8 @@ abstract class Access {
 		}
 		$ldapname = $this->sanitizeUsername($ldapname);
 
-		//a new user/group! Then let's try to add it. We're shooting into the blue with the user/group name, assuming that in most cases there will not be a conflict. Otherwise an error will occur and we will continue with our second shot.
-		if(($isUser && !\OCP\User::userExists($ldapname)) || (!$isUser && !\OC_Group::groupExists($ldapname))) {
+		//a new user/group! Add it only if it doesn't conflict with other backend's users or existing groups
+		if(($isUser && !\OCP\User::userExists($ldapname, 'OCA\\user_ldap\\USER_LDAP')) || (!$isUser && !\OC_Group::groupExists($ldapname))) {
 			if($this->mapComponent($dn, $ldapname, $isUser)) {
 				return $ldapname;
 			}
@@ -874,4 +874,4 @@ abstract class Access {
 		return $pagedSearchOK;
 	}
 
-}
\ No newline at end of file
+}