Ticket #42016: filter-validate-file-results.diff

wp-includes/functions.php

@@ -4252 +4252 @@
  * @return int 0 means nothing is wrong, greater than 0 means something was wrong.
  */
 function validate_file( $file, $allowed_files = '' ) {
-        if ( false !== strpos( $file, '..' ) )
-                return 1;
+        $result = 0;
 
-        if ( false !== strpos( $file, './' ) )
-                return 1;
+        if (':' == substr( $file, 1, 1 ) )
+                $result = 2;
 
         if ( ! empty( $allowed_files ) && ! in_array( $file, $allowed_files ) )
-                return 3;
+                $result = 3;
 
-        if (':' == substr( $file, 1, 1 ) )
-                return 2;
+        if ( false !== strpos( $file, '..' ) )
+                $result = 1;
 
-        return 0;
+        if ( false !== strpos( $file, './' ) )
+                $result = 1;
+
+        /**
+         * Filters the returned result.
+         *
+         * @since 4.8.3
+         *
+         * @param int As described for the return value of the function.
+         * @param string $file As provided to the function (file path).
+         * @param array  $allowed_files As provided to the function (list of allowed files).
+         */
+        return apply_filters( 'validate_file', $result, $file, $allowed_files );
 }
 
 /**