Special:Upload should not crash on failing previews

A thumbnail transformation can fail, but the preview on Special:Upload
was not accounting for failed previews and caused a stacktrace on
accessing getUrl on 'false'.

Bug: T155771
Change-Id: Iff3a2ae3512a34a2d2efb981b7ea85da71aaf637

diff --git a/includes/specials/SpecialUpload.php b/includes/specials/SpecialUpload.php
index 8b8e514..c5a1f27 100644 (file)
--- a/includes/specials/SpecialUpload.php
+++ b/includes/specials/SpecialUpload.php
@@ -1090,12 +1090,14 @@ class UploadForm extends HTMLForm {
                                global $wgContLang;
 
                                $mto = $file->transform( [ 'width' => 120 ] );
-                               $this->addHeaderText(
-                                       '<div class="thumb t' . $wgContLang->alignEnd() . '">' .
-                                       Html::element( 'img', [
-                                               'src' => $mto->getUrl(),
-                                               'class' => 'thumbimage',
-                                       ] ) . '</div>', 'description' );
+                               if ( $mto ) {
+                                       $this->addHeaderText(
+                                               '<div class="thumb t' . $wgContLang->alignEnd() . '">' .
+                                               Html::element( 'img', [
+                                                       'src' => $mto->getUrl(),
+                                                       'class' => 'thumbimage',
+                                               ] ) . '</div>', 'description' );
+                               }
                        }
                }