Ticket #60398: 60398.diff

src/wp-admin/includes/class-file-upload-upgrader.php

@@ -75 +75 @@
                                 /** This filter is documented in wp-admin/includes/file.php */
                                 if ( class_exists( 'ZipArchive', false ) && apply_filters( 'unzip_file_use_ziparchive', true ) ) {
                                         $archive          = new ZipArchive();
-                                        $archive_is_valid = $archive->open( $file['file'], ZIPARCHIVE::CHECKCONS );
+                                        $archive_is_valid = $archive->open( $file['file'], ZipArchive::CHECKCONS );
 
                                         if ( true === $archive_is_valid ) {
                                                 $archive->close();
                                         }
-                                } else {
+                                }
+
+                                /*
+                                 * Use PclZip if:
+                                 * - ZipArchive is unavailable.
+                                 * - ZipArchive is disabled.
+                                 * - ZipArchive was unable to successfully open the ZIP.
+                                 *     This may indicate a ZIP archive is inconsistent, which
+                                 *     should not block its installation.
+                                 *     @see https://core.trac.wordpress.org/ticket/60398
+                                 */
+                                if ( true !== $archive_is_valid ) {
                                         require_once ABSPATH . 'wp-admin/includes/class-pclzip.php';
 
                                         $archive          = new PclZip( $file['file'] );