Bug #78052 [Ver]: exif_read_data chokes on strict_types for parameter 2

Edit report at https://bugs.php.net/bug.php?id=78052&edit=1 ID: 78052 Updated by: requinix@php.net Reported by: c dot schiffler at cyberspectrum dot de Summary: exif_read_data chokes on strict_types for parameter 2 Status: Verified Type: Bug Package: EXIF related Operating System: Linux PHP Version: 7.3.5 Block user comment: N Private report: N New Comment: Yeah, on second thought an empty string would be weird - PHP does null everywhere for optional arguments, no reason to go against that here. But since someone will be in there anyways I think adding the ZSTR_LEN check is worth it, for hypothetical code like $sections = []; if ($should_get_file) $sections[] = "FILE"; if ($should_get_thumbnail) $sections[] = "THUMBNAIL"; $return = exif_read_data($stream, implode(",", $sections)); Previous Comments: ------------------------------------------------------------------------ [2019-05-23 09:20:36] nikic@php.net Agree with cmb, I think it would be better to allow an explicit null here. ------------------------------------------------------------------------ [2019-05-22 22:33:24] cmb@php.net An alternative would be to actually allow passing NULL, i.e. Z_PARAM_STR_EX(z_sections_needed, 1, 0) ------------------------------------------------------------------------ [2019-05-22 19:21:47] requinix@php.net This could be a doc bug (have the argument default to "") however the source tests specifically for null to decide if it should process the argument at all so passing an empty string loses a bit of performance. I think -if (z_sections_needed) { +if (z_sections_needed && ZSTR_LEN(z_sections_needed)) { Then the small edit to the doc for string $sections = "" ------------------------------------------------------------------------ [2019-05-22 19:19:56] spam2 at rhsoft dot net param 2 is type string . period exif_read_data ( mixed $stream [, string $sections = NULL [, bool $arrays = FALSE [, bool $thumbnail = FALSE ]]] ) : array ------------------------------------------------------------------------ [2019-05-22 19:10:51] c dot schiffler at cyberspectrum dot de Description: ------------ Calling exif_read_data with null as second optional parameter results in a type error. This results in impossibility to call exif_read_data having different values for parameter 3&4 but sticking to the null default of parameter 2. Test script: --------------- declare(strict_types=1); // This errors out but should not. exif_read_data('image.jpg', null, true, false); // This is a workaround currently in use as internal functions are not affected by strict_types per https://bugs.php.net/bug.php?id=74750 call_user_func('exif_read_data', 'image.jpg', null, true, false); Expected result: ---------------- Data should be extracted. Actual result: -------------- TypeError: exif_read_data() expects parameter 2 to be string, null given ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=78052&edit=1