+/**
+ * Attempt to determine the real file type of a file.
+ * If unable to, the file name extension will be used to determine type.
+ *
+ * If it's determined that the extension does not match the file's real type,
+ * then the "proper_filename" value will be set with a proper filename and extension.
+ *
+ * Currently this function only supports validating images known to getimagesize().
+ *
+ * @since 3.0.0
+ *
+ * @param string $file Full path to the image.
+ * @param string $filename The filename of the image (may differ from $file due to $file being in a tmp directory)
+ * @param array $mimes Optional. Key is the file extension with value as the mime type.
+ * @return array Values for the extension, MIME, and either a corrected filename or false if original $filename is valid
+ */
+function wp_check_filetype_and_ext( $file, $filename, $mimes = null ) {
+
+ $proper_filename = false;
+
+ // Do basic extension validation and MIME mapping
+ $wp_filetype = wp_check_filetype( $filename, $mimes );
+ extract( $wp_filetype );
+
+ // We can't do any further validation without a file to work with
+ if ( ! file_exists( $file ) )
+ return compact( 'ext', 'type', 'proper_filename' );
+
+ // We're able to validate images using GD
+ if ( $type && 0 === strpos( $type, 'image/' ) && function_exists('getimagesize') ) {
+
+ // Attempt to figure out what type of image it actually is
+ $imgstats = @getimagesize( $file );
+
+ // If getimagesize() knows what kind of image it really is and if the real MIME doesn't match the claimed MIME
+ if ( !empty($imgstats['mime']) && $imgstats['mime'] != $type ) {
+ // This is a simplified array of MIMEs that getimagesize() can detect and their extensions
+ // You shouldn't need to use this filter, but it's here just in case
+ $mime_to_ext = apply_filters( 'getimagesize_mimes_to_exts', array(
+ 'image/jpeg' => 'jpg',
+ 'image/png' => 'png',
+ 'image/gif' => 'gif',
+ 'image/bmp' => 'bmp',
+ 'image/tiff' => 'tif',
+ ) );
+
+ // Replace whatever is after the last period in the filename with the correct extension
+ if ( ! empty( $mime_to_ext[ $imgstats['mime'] ] ) ) {
+ $filename_parts = explode( '.', $filename );
+ array_pop( $filename_parts );
+ $filename_parts[] = $mime_to_ext[ $imgstats['mime'] ];
+ $new_filename = implode( '.', $filename_parts );
+
+ if ( $new_filename != $filename )
+ $proper_filename = $new_filename; // Mark that it changed
+
+ // Redefine the extension / MIME
+ $wp_filetype = wp_check_filetype( $new_filename, $mimes );
+ extract( $wp_filetype );
+ }
+ }
+ }
+
+ // Let plugins try and validate other types of files
+ // Should return an array in the style of array( 'ext' => $ext, 'type' => $type, 'proper_filename' => $proper_filename )
+ return apply_filters( 'wp_check_filetype_and_ext', compact( 'ext', 'type', 'proper_filename' ), $file, $filename, $mimes );
+}
+