Why file upload error codes in php miss number '5'?

Question

I am writing a custom error handling/reporting function for php file upload and I noticed that the error codes returned is one of numbers 0 to 8 except 5.

Is this a typo in the source I am using or is it really this way? And if it is so, I am curious why they have skipped number '5'.

Thanks.

Edit In response to Pekka here are the error codes I found explained in my PHP manual.

UPLOAD_ERR_OK Value: 0; There is no error, the file uploaded with success.

UPLOAD_ERR_INI_SIZE Value: 1; The uploaded file exceeds the upload_max_filesize directive in php.ini.

UPLOAD_ERR_FORM_SIZE Value: 2; The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.

UPLOAD_ERR_PARTIAL Value: 3; The uploaded file was only partially uploaded.

UPLOAD_ERR_NO_FILE Value: 4; No file was uploaded.

UPLOAD_ERR_NO_TMP_DIR Value: 6; Missing a temporary folder. Introduced in PHP 4.3.10 and PHP 5.0.3.

UPLOAD_ERR_CANT_WRITE Value: 7; Failed to write file to disk. Introduced in PHP 5.1.0.

UPLOAD_ERR_EXTENSION Value: 8; File upload stopped by extension. Introduced in PHP 5.2.0.

Answer 1

It doesn't matter as you use the UPLOAD_ERR_* constants anyway. But I guess the field 5 was an error which is now handled by a different error case.

Edit

The case "5" was an error for empty uploaded files. However this isn't an error so the field/constant got removed. See changeset 81792 on main/rfc1867.c and changeset 88408 on main/rfc1867.c