We have OutputPage::showPermissionsErrorPage() for that

diff --git a/includes/ProtectionForm.php b/includes/ProtectionForm.php
index 9fb1337..c836352 100644 (file)
--- a/includes/ProtectionForm.php
+++ b/includes/ProtectionForm.php
@@ -232,7 +232,7 @@ class ProtectionForm {
                        if( wfReadOnly() ) {
                                $wgOut->readOnlyPage();
                        } elseif( $this->mPermErrors ) {
-                               $wgOut->addWikiText( $wgOut->formatPermissionsErrorMessage( $this->mPermErrors ) );
+                               $wgOut->showPermissionsErrorPage( $this->mPermErrors );
                        }
                } else {
                        $wgOut->addWikiMsg( 'protect-text', $this->mTitle->getPrefixedText() );