Ticket #39422: 39422.patch

src/wp-includes/class-wp-image-editor-gd.php

@@ -432 +432 @@
                         'file'      => wp_basename( apply_filters( 'image_make_intermediate_size', $filename ) ),
                         'width'     => $this->size['width'],
                         'height'    => $this->size['height'],
-                        'mime-type' => $mime_type,
+                        'mime_type' => $mime_type,
                 );
         }
 

src/wp-includes/class-wp-image-editor-imagick.php

@@ -652 +652 @@
                         'file'      => wp_basename( apply_filters( 'image_make_intermediate_size', $filename ) ),
                         'width'     => $this->size['width'],
                         'height'    => $this->size['height'],
-                        'mime-type' => $mime_type,
+                        'mime_type' => $mime_type,
                 );
         }