Index: src/wp-includes/media.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/wp-includes/media.php	(revision 35948)
+++ src/wp-includes/media.php	(revision )
@@ -1296,7 +1296,7 @@
 	$all_sizes[] = $base_url . $image_meta['file'];
 
 	// Bail early if the image src doesn't match any of the known image sizes.
-	if ( ! in_array( $image_src, $all_sizes ) ) {
+	if ( ! in_array( $image_src, $all_sizes ) && ! apply_filters( 'known_image_src_in_image_sizes', false, $image_src, $image_meta, $attachment_id )) {
 		return $image;
 	}