Avoid fatal on login if username is invalid title

Steps to reproduce: Try logging in with a 256-character username.

Expected result: Friendly error message saying the name is invalid.

Actual result: Fatal error: Call to a member function getName() on a
non-object in /var/www/git-trunk/phase3/includes/specials/SpecialUserlogin.php
on line 433

Fix: If you want to check whether something is a User object, check
whether it's a User object.  There are things other than null that don't
behave like User objects.

diff --git a/includes/specials/SpecialUserlogin.php b/includes/specials/SpecialUserlogin.php
index baced16..5d5a771 100644 (file)
--- a/includes/specials/SpecialUserlogin.php
+++ b/includes/specials/SpecialUserlogin.php
@@ -430,7 +430,7 @@ class LoginForm {
                # TODO: Allow some magic here for invalid external names, e.g., let the
                # user choose a different wiki name.
                $u = User::newFromName( $this->mName );
-               if( is_null( $u ) || !User::isUsableName( $u->getName() ) ) {
+               if( !( $u instanceof User ) || !User::isUsableName( $u->getName() ) ) {
                        return self::ILLEGAL;
                }