Protect API metadata keys from FormatMetadata::fetchExtendedMetadata()

Bug: T97469
Change-Id: If5d101231ca913621c88e6683f6ef07f6dae1ee8

diff --git a/includes/media/FormatMetadata.php b/includes/media/FormatMetadata.php
index 0c6b6c7..2ae5af3 100644 (file)
--- a/includes/media/FormatMetadata.php
+++ b/includes/media/FormatMetadata.php
@@ -1604,7 +1604,7 @@ class FormatMetadata extends ContextSource {
                        // This is an API-specific function so it would be cleaner to call it from
                        // outside fetchExtendedMetadata, but this way we don't need to redo the
                        // computation on a cache hit.
-                       $this->sanitizeArrayForXml( $extendedMetadata );
+                       $this->sanitizeArrayForAPI( $extendedMetadata );
                        $valueToCache = array( 'data' => $extendedMetadata, 'timestamp' => wfTimestampNow() );
                        $wgMemc->set( $cacheKey, $valueToCache, $maxCacheTime );
                }
@@ -1800,17 +1800,16 @@ class FormatMetadata extends ContextSource {
 
        /**
         * Makes sure the given array is a valid API response fragment
-        * (can be transformed into XML)
         * @param array $arr
         */
-       protected function sanitizeArrayForXml( &$arr ) {
+       protected function sanitizeArrayForAPI( &$arr ) {
                if ( !is_array( $arr ) ) {
                        return;
                }
 
                $counter = 1;
                foreach ( $arr as $key => &$value ) {
-                       $sanitizedKey = $this->sanitizeKeyForXml( $key );
+                       $sanitizedKey = $this->sanitizeKeyForAPI( $key );
                        if ( $sanitizedKey !== $key ) {
                                if ( isset( $arr[$sanitizedKey] ) ) {
                                        // Make the sanitized keys hopefully unique.
@@ -1824,20 +1823,24 @@ class FormatMetadata extends ContextSource {
                                unset( $arr[$key] );
                        }
                        if ( is_array( $value ) ) {
-                               $this->sanitizeArrayForXml( $value );
+                               $this->sanitizeArrayForAPI( $value );
                        }
                }
+
+               // Handle API metadata keys (particularly "_type")
+               $keys = array_filter( array_keys( $arr ), 'ApiResult::isMetadataKey' );
+               if ( $keys ) {
+                       ApiResult::setPreserveKeysList( $arr, $keys );
+               }
        }
 
        /**
-        * Turns a string into a valid XML identifier.
-        * Used to ensure that keys of an associative array in the
-        * API response do not break the XML formatter.
+        * Turns a string into a valid API identifier.
         * @param string $key
         * @return string
         * @since 1.23
         */
-       protected function sanitizeKeyForXml( $key ) {
+       protected function sanitizeKeyForAPI( $key ) {
                // drop all characters which are not valid in an XML tag name
                // a bunch of non-ASCII letters would be valid but probably won't
                // be used so we take the easy way