Ticket #48518: 48518.diff

src/wp-admin/includes/image.php

@@ -90 +90 @@
                 return $registered_sizes;
         }
 
-        $full_width     = (int) $image_meta['width'];
-        $full_height    = (int) $image_meta['height'];
+        // Use the originally uploaded image dimensions as full_width and full_height.
+        if ( ! empty( $image_meta['original_image'] ) ) {
+                $image_file = wp_get_original_image_path( $attachment_id );
+                $imagesize  = @getimagesize( $image_file );
+        }
+
+        if ( ! empty( $imagesize ) ) {
+                $full_width  = $imagesize[0];
+                $full_height = $imagesize[1];
+        } else {
+                $full_width  = (int) $image_meta['width'];
+                $full_height = (int) $image_meta['height'];
+        }
+
         $possible_sizes = array();
 
         // Skip registered sizes that are too large for the uploaded image.