Upload: fix `wp_unique_filename()` to prevent name collisions with existing or future image sub-size file names, and add unit tests.

Props Viper007Bond, pbiron, azaozz.
Fixes #42437.
Built from https://develop.svn.wordpress.org/trunk@46822


git-svn-id: http://core.svn.wordpress.org/trunk@46622 1a063a9b-81f0-0310-95a4-ce76da25c4cd
This commit is contained in:
Andrew Ozz 2019-12-06 22:28:00 +00:00
parent aa1fdcbd52
commit 15a566edef
2 changed files with 85 additions and 23 deletions

View File

@ -2409,6 +2409,7 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
// Separate the filename into a name and extension.
$ext = pathinfo( $filename, PATHINFO_EXTENSION );
$name = pathinfo( $filename, PATHINFO_BASENAME );
if ( $ext ) {
$ext = '.' . $ext;
}
@ -2426,6 +2427,15 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
$filename = call_user_func( $unique_filename_callback, $dir, $name, $ext );
} else {
$number = '';
$fname = pathinfo( $filename, PATHINFO_FILENAME );
// Always append a number to file names that can potentially match image sub-size file names.
if ( $fname && preg_match( '/-(?:\d+x\d+|scaled|rotated)$/', $fname ) ) {
$number = 1;
// At this point the file name may not be unique. This is tested below and the $number is incremented.
$filename = str_replace( "{$fname}{$ext}", "{$fname}-{$number}{$ext}", $filename );
}
// Change '.ext' to lower case.
if ( $ext && strtolower( $ext ) != $ext ) {
@ -2433,41 +2443,93 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
$filename2 = preg_replace( '|' . preg_quote( $ext ) . '$|', $ext2, $filename );
// Check for both lower and upper case extension or image sub-sizes may be overwritten.
while ( file_exists( $dir . "/$filename" ) || file_exists( $dir . "/$filename2" ) ) {
while ( file_exists( $dir . "/{$filename}" ) || file_exists( $dir . "/{$filename2}" ) ) {
$new_number = (int) $number + 1;
$filename = str_replace( array( "-$number$ext", "$number$ext" ), "-$new_number$ext", $filename );
$filename2 = str_replace( array( "-$number$ext2", "$number$ext2" ), "-$new_number$ext2", $filename2 );
$filename = str_replace( array( "-{$number}{$ext}", "{$number}{$ext}" ), "-{$new_number}{$ext}", $filename );
$filename2 = str_replace( array( "-{$number}{$ext2}", "{$number}{$ext2}" ), "-{$new_number}{$ext2}", $filename2 );
$number = $new_number;
}
/**
* Filters the result when generating a unique file name.
*
* @since 4.5.0
*
* @param string $filename Unique file name.
* @param string $ext File extension, eg. ".png".
* @param string $dir Directory path.
* @param callable|null $unique_filename_callback Callback function that generates the unique file name.
*/
return apply_filters( 'wp_unique_filename', $filename2, $ext, $dir, $unique_filename_callback );
$filename = $filename2;
} else {
while ( file_exists( $dir . "/{$filename}" ) ) {
$new_number = (int) $number + 1;
if ( '' === "{$number}{$ext}" ) {
$filename = "{$filename}-{$new_number}";
} else {
$filename = str_replace( array( "-{$number}{$ext}", "{$number}{$ext}" ), "-{$new_number}{$ext}", $filename );
}
$number = $new_number;
}
}
while ( file_exists( $dir . "/$filename" ) ) {
$new_number = (int) $number + 1;
if ( '' == "$number$ext" ) {
$filename = "$filename-" . $new_number;
} else {
$filename = str_replace( array( "-$number$ext", "$number$ext" ), '-' . $new_number . $ext, $filename );
// Prevent collisions with existing file names that contain dimension-like strings
// (whether they are subsizes or originals uploaded prior to #42437).
// The (resized) image files would have name and extension, and will be in the uploads dir.
if ( @is_dir( $dir ) && $name && $ext ) {
// List of all files and directories contained in $dir (with the "dot" files removed).
$files = array_diff( scandir( $dir ), array( '.', '..' ) );
if ( ! empty( $files ) ) {
while ( _wp_check_existing_file_names( $filename, $files ) ) {
$new_number = (int) $number + 1;
$filename = str_replace( array( "-{$number}{$ext}", "{$number}{$ext}" ), "-{$new_number}{$ext}", $filename );
$number = $new_number;
}
}
$number = $new_number;
}
}
/** This filter is documented in wp-includes/functions.php */
/**
* Filters the result when generating a unique file name.
*
* @since 4.5.0
*
* @param string $filename Unique file name.
* @param string $ext File extension, eg. ".png".
* @param string $dir Directory path.
* @param callable|null $unique_filename_callback Callback function that generates the unique file name.
*/
return apply_filters( 'wp_unique_filename', $filename, $ext, $dir, $unique_filename_callback );
}
/**
* Helper function to check if a file name could match an existing image sub-size file name.
*
* @since 5.3.1
* @access private
*
* @param string $filename The file name to check.
* $param array $files An array of existing files in the directory.
* $return bool True if the tested file name could match an existing file, false otherwise.
*/
function _wp_check_existing_file_names( $filename, $files ) {
$fname = pathinfo( $filename, PATHINFO_FILENAME );
$ext = pathinfo( $filename, PATHINFO_EXTENSION );
// Edge case, file names like `.ext`
if ( empty( $fname ) ) {
return false;
}
if ( $ext ) {
$ext = ".$ext";
}
$regex = '/^' . preg_quote( $fname ) . '-(?:\d+x\d+|scaled|rotated)' . preg_quote( $ext ) . '$/';
foreach ( $files as $file ) {
if ( preg_match( $regex, $file ) ) {
return true;
}
}
return false;
}
/**
* Create a file in the upload folder with given content.
*

View File

@ -13,7 +13,7 @@
*
* @global string $wp_version
*/
$wp_version = '5.4-alpha-46821';
$wp_version = '5.4-alpha-46822';
/**
* Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.