// For 404 handled thumbnails, we only use the base name of the URI
// for the thumb params and the parent directory for the source file name.
- // Check that the zone relative path matches up so squid caches won't pick
+ // Check that the zone relative path matches up so CDN caches won't pick
// up thumbs that would not be purged on source file deletion (T36231).
if ( $rel404 !== null ) { // thumbnail was handled via 404
if ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName ) ) {
// Send request to proxied service
$status = $req->execute();
+ MediaWiki\HeaderCallback::warnIfHeadersSent();
+
// Simply serve the response from the proxied service as-is
header( 'HTTP/1.1 ' . $req->getStatus() );
function wfThumbError( $status, $msgHtml, $msgText = null, $context = [] ) {
global $wgShowHostnames;
+ MediaWiki\HeaderCallback::warnIfHeadersSent();
+
header( 'Cache-Control: no-cache' );
header( 'Content-Type: text/html; charset=utf-8' );
if ( $status == 400 || $status == 404 || $status == 429 ) {