Ticket #24380: 24380.3.diff

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

@@ -383 +383 @@
                         if ( function_exists('imageistruecolor') && ! imageistruecolor( $image ) )
                                 imagetruecolortopalette( $image, false, imagecolorstotal( $image ) );
 
-                        if ( ! $this->make_image( $filename, 'imagepng', array( $image, $filename ) ) )
+                        /*
+                         * Invert the 1-100 quality scale and constrain it to 0-9,
+                         * as per imagepng()'s peculiar quality parameter.
+                         */
+                        $compression_level = floor( ( 101 - $this->quality ) * 0.09 );
+
+                        if ( ! $this->make_image( $filename, 'imagepng', array( $image, $filename, $compression_level ) ) ) {
                                 return new WP_Error( 'image_save_error', __('Image Editor Save Failed') );
+                        }
                 }
                 elseif ( 'image/jpeg' == $mime_type ) {
                         if ( ! $this->make_image( $filename, 'imagejpeg', array( $image, $filename, $this->quality ) ) )