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Ignore:
Timestamp:
08/24/2021 08:50:21 PM (3 years ago)
Author:
azaozz
Message:

Media: Fix wp_unique_filename() to check for name collisions with all alternate file names when an image may be converted after uploading. This includes possible collinions with pre-existing images whose sub-sizes/thumbnails are regenerated.

Props ianmjones, azaozz.
Fixes #53668.

File:
1 edited

Legend:

Unmodified
Added
Removed
  • trunk/src/wp-includes/functions.php

    r51625 r51653  
    24892489    $ext2     = null;
    24902490
     2491    // Initialize vars used in the wp_unique_filename filter.
     2492    $number        = '';
     2493    $alt_filenames = array();
     2494
    24912495    // Separate the filename into a name and extension.
    24922496    $ext  = pathinfo( $filename, PATHINFO_EXTENSION );
     
    25092513        $filename = call_user_func( $unique_filename_callback, $dir, $name, $ext );
    25102514    } else {
    2511         $number = '';
    2512         $fname  = pathinfo( $filename, PATHINFO_FILENAME );
     2515        $fname = pathinfo( $filename, PATHINFO_FILENAME );
    25132516
    25142517        // Always append a number to file names that can potentially match image sub-size file names.
     
    25202523        }
    25212524
    2522         // Change '.ext' to lower case.
    2523         if ( $ext && strtolower( $ext ) != $ext ) {
    2524             $ext2      = strtolower( $ext );
    2525             $filename2 = preg_replace( '|' . preg_quote( $ext ) . '$|', $ext2, $filename );
    2526 
    2527             // Check for both lower and upper case extension or image sub-sizes may be overwritten.
    2528             while ( file_exists( $dir . "/{$filename}" ) || file_exists( $dir . "/{$filename2}" ) ) {
    2529                 $new_number = (int) $number + 1;
    2530                 $filename   = str_replace( array( "-{$number}{$ext}", "{$number}{$ext}" ), "-{$new_number}{$ext}", $filename );
    2531                 $filename2  = str_replace( array( "-{$number}{$ext2}", "{$number}{$ext2}" ), "-{$new_number}{$ext2}", $filename2 );
    2532                 $number     = $new_number;
     2525        // Get the mime type. Uploaded files were already checked with wp_check_filetype_and_ext()
     2526        // in _wp_handle_upload(). Using wp_check_filetype() would be sufficient here.
     2527        $file_type = wp_check_filetype( $filename );
     2528        $mime_type = $file_type['type'];
     2529
     2530        $is_image    = ( ! empty( $mime_type ) && 0 === strpos( $mime_type, 'image/' ) );
     2531        $upload_dir  = wp_get_upload_dir();
     2532        $lc_filename = null;
     2533
     2534        $lc_ext = strtolower( $ext );
     2535        $_dir   = trailingslashit( $dir );
     2536
     2537        // If the extension is uppercase add an alternate file name with lowercase extension. Both need to be tested
     2538        // for uniqueness as the extension will be changed to lowercase for better compatibility with different filesystems.
     2539        // Fixes an inconsistency in WP < 2.9 where uppercase extensions were allowed but image sub-sizes were created with
     2540        // lowercase extensions.
     2541        if ( $ext && $lc_ext !== $ext ) {
     2542            $lc_filename = preg_replace( '|' . preg_quote( $ext ) . '$|', $lc_ext, $filename );
     2543        }
     2544
     2545        // Increment the number added to the file name if there are any files in $dir whose names match one of the
     2546        // possible name variations.
     2547        while ( file_exists( $_dir . $filename ) || ( $lc_filename && file_exists( $_dir . $lc_filename ) ) ) {
     2548            $new_number = (int) $number + 1;
     2549
     2550            if ( $lc_filename ) {
     2551                $lc_filename = str_replace( array( "-{$number}{$lc_ext}", "{$number}{$lc_ext}" ), "-{$new_number}{$lc_ext}", $lc_filename );
    25332552            }
    25342553
    2535             $filename = $filename2;
    2536         } else {
    2537             while ( file_exists( $dir . "/{$filename}" ) ) {
    2538                 $new_number = (int) $number + 1;
    2539 
    2540                 if ( '' === "{$number}{$ext}" ) {
    2541                     $filename = "{$filename}-{$new_number}";
    2542                 } else {
    2543                     $filename = str_replace( array( "-{$number}{$ext}", "{$number}{$ext}" ), "-{$new_number}{$ext}", $filename );
    2544                 }
    2545 
    2546                 $number = $new_number;
     2554            if ( '' === "{$number}{$ext}" ) {
     2555                $filename = "{$filename}-{$new_number}";
     2556            } else {
     2557                $filename = str_replace( array( "-{$number}{$ext}", "{$number}{$ext}" ), "-{$new_number}{$ext}", $filename );
    25472558            }
     2559
     2560            $number = $new_number;
     2561        }
     2562
     2563        // Change the extension to lowercase if needed.
     2564        if ( $lc_filename ) {
     2565            $filename = $lc_filename;
    25482566        }
    25492567
    25502568        // Prevent collisions with existing file names that contain dimension-like strings
    25512569        // (whether they are subsizes or originals uploaded prior to #42437).
    2552         $upload_dir = wp_get_upload_dir();
     2570
     2571        $files = array();
     2572        $count = 10000;
    25532573
    25542574        // The (resized) image files would have name and extension, and will be in the uploads dir.
     
    25802600
    25812601            if ( ! empty( $files ) ) {
    2582                 // The extension case may have changed above.
    2583                 $new_ext = ! empty( $ext2 ) ? $ext2 : $ext;
     2602                $count = count( $files );
    25842603
    25852604                // Ensure this never goes into infinite loop
    25862605                // as it uses pathinfo() and regex in the check, but string replacement for the changes.
    2587                 $count = count( $files );
    2588                 $i     = 0;
     2606                $i = 0;
    25892607
    25902608                while ( $i <= $count && _wp_check_existing_file_names( $filename, $files ) ) {
    25912609                    $new_number = (int) $number + 1;
    2592                     $filename   = str_replace( array( "-{$number}{$new_ext}", "{$number}{$new_ext}" ), "-{$new_number}{$new_ext}", $filename );
    2593                     $number     = $new_number;
     2610
     2611                    // If $ext is uppercase it was replaced with the lowercase version after the previous loop.
     2612                    $filename = str_replace( array( "-{$number}{$lc_ext}", "{$number}{$lc_ext}" ), "-{$new_number}{$lc_ext}", $filename );
     2613
     2614                    $number = $new_number;
    25942615                    $i++;
    25952616                }
    25962617            }
    25972618        }
     2619
     2620        // Check if an image will be converted after uploading or some existing images sub-sizes file names may conflict
     2621        // when regenerated. If yes, ensure the new file name will be unique and will produce unique sub-sizes.
     2622        if ( $is_image ) {
     2623            $output_formats = apply_filters( 'image_editor_output_format', array(), $_dir . $filename, $mime_type );
     2624            $alt_types      = array();
     2625
     2626            if ( ! empty( $output_formats[ $mime_type ] ) ) {
     2627                // The image will be converted to this format/mime type.
     2628                $alt_mime_type = $output_formats[ $mime_type ];
     2629
     2630                // Other types of images whose names may conflict if their sub-sizes are regenerated.
     2631                $alt_types = array_keys( array_intersect( $output_formats, array( $mime_type, $alt_mime_type ) ) );
     2632                $alt_types[] = $alt_mime_type;
     2633            } elseif ( ! empty( $output_formats ) ) {
     2634                $alt_types = array_keys( array_intersect( $output_formats, array( $mime_type ) ) );
     2635            }
     2636
     2637            // Remove duplicates and the original mime type. It will be added later if needed.
     2638            $alt_types = array_unique( array_diff( $alt_types, array( $mime_type ) ) );
     2639
     2640            foreach ( $alt_types as $alt_type ) {
     2641                $alt_ext = wp_get_default_extension_for_mime_type( $alt_type );
     2642
     2643                if ( ! $alt_ext ) {
     2644                    continue;
     2645                }
     2646
     2647                $alt_ext      = ".{$alt_ext}";
     2648                $alt_filename = preg_replace( '|' . preg_quote( $lc_ext ) . '$|', $alt_ext, $filename );
     2649
     2650                $alt_filenames[ $alt_ext ] = $alt_filename;
     2651            }
     2652
     2653            if ( ! empty( $alt_filenames ) ) {
     2654                // Add the original filename. It needs to be checked again together with the alternate filenames
     2655                // when $number is incremented.
     2656                $alt_filenames[ $lc_ext ] = $filename;
     2657
     2658                // Ensure no infinite loop.
     2659                $i = 0;
     2660
     2661                while ( $i <= $count && _wp_check_alternate_file_names( $alt_filenames, $_dir, $files ) ) {
     2662                    $new_number = (int) $number + 1;
     2663
     2664                    foreach ( $alt_filenames as $alt_ext => $alt_filename ) {
     2665                        $alt_filenames[ $alt_ext ] = str_replace( array( "-{$number}{$alt_ext}", "{$number}{$alt_ext}" ), "-{$new_number}{$alt_ext}", $alt_filename );
     2666                    }
     2667
     2668                    // Also update the $number in (the output) $filename.
     2669                    // If the extension was uppercase it was already replaced with the lowercase version.
     2670                    $filename = str_replace( array( "-{$number}{$lc_ext}", "{$number}{$lc_ext}" ), "-{$new_number}{$lc_ext}", $filename );
     2671
     2672                    $number = $new_number;
     2673                    $i++;
     2674                }
     2675            }
     2676        }
    25982677    }
    25992678
     
    26022681     *
    26032682     * @since 4.5.0
     2683     * @since 5.8.1 The `$alt_filenames` and `$number` parameters were added.
    26042684     *
    26052685     * @param string        $filename                 Unique file name.
     
    26072687     * @param string        $dir                      Directory path.
    26082688     * @param callable|null $unique_filename_callback Callback function that generates the unique file name.
     2689     * @param string[]      $alt_filenames            Array of alternate file names that were checked for collisions.
     2690     * @param int|string    $number                   The highest number that was used to make the file name unique
     2691     *                                                or an empty string if unused.
    26092692     */
    2610     return apply_filters( 'wp_unique_filename', $filename, $ext, $dir, $unique_filename_callback );
     2693    return apply_filters( 'wp_unique_filename', $filename, $ext, $dir, $unique_filename_callback, $alt_filenames, $number );
     2694}
     2695
     2696/**
     2697 * Helper function to test if each of an array of file names could conflict with existing files.
     2698 *
     2699 * @since 5.8.1
     2700 * @access private
     2701 *
     2702 * @param string[] $filenames Array of file names to check.
     2703 * @param string   $dir       The directory containing the files.
     2704 * @param array    $files     An array of existing files in the directory. May be empty.
     2705 * @return bool True if the tested file name could match an existing file, false otherwise.
     2706 */
     2707function _wp_check_alternate_file_names( $filenames, $dir, $files ) {
     2708    foreach ( $filenames as $filename ) {
     2709        if ( file_exists( $dir . $filename ) ) {
     2710            return true;
     2711        }
     2712
     2713        if ( ! empty( $files ) && _wp_check_existing_file_names( $filename, $files ) ) {
     2714            return true;
     2715        }
     2716    }
     2717
     2718    return false;
    26112719}
    26122720
     
    27922900        }
    27932901    }
     2902}
     2903
     2904/**
     2905 * Returns first matched extension for the mime-type,
     2906 * as mapped from wp_get_mime_types().
     2907 *
     2908 * @since 5.8.1
     2909 *
     2910 * @param string $mime_type
     2911 *
     2912 * @return string|false
     2913 */
     2914function wp_get_default_extension_for_mime_type( $mime_type ) {
     2915    $extensions = explode( '|', array_search( $mime_type, wp_get_mime_types(), true ) );
     2916
     2917    if ( empty( $extensions[0] ) ) {
     2918        return false;
     2919    }
     2920
     2921    return $extensions[0];
    27942922}
    27952923
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