In FdpiFacturx, the SetPdfVersion function is broken.

[Billy-1971]

In FdpiFacturx, the SetPdfVersion function is broken.

PHP chr only accepts values from 0-255, values from 127-256 are generated via rand.

Therefore, from time to time the PDF is not valid, error: The aforementioned EOL marker shall be immediately followed by a % (25h) character followed by at least four bytes, each of whose encoded byte values shall have a decimal value greater than 127

Original:
$this->PDFVersion .= "\n" . '%' . chr(rand(128, 256)) . chr(rand(128, 256)) . chr(rand(128, 256)) . chr(rand(128, 256));
New:
$this->PDFVersion .= "\n" . '%' . chr(rand(127, 255)) . chr(rand(127, 255)) . chr(rand(127, 255)) . chr(rand(127, 255)); // chr 0-255

[benito103e]

Hello,
Thank you for your issue, please don't be offended by my question: but are you human?
If so, in what context did you encounter this error?
Thank you in advance for your clarification, before I dig deeper into the subject.

[Billy-1971]

Hello,
i am a human, i come from Germany and unfortunately my English is very bad, so I have partially machine translated the text.

The problem occurs when i create a ZUGFeRD PDF from a PDF and a facturx.xml using Writer via "generate". The problem occurs approximately once every 30-50 times.

The error message comes from the Verapdf Validator, because i validate each PDF after it is created.

[benito103e]

Hello Billy,
Thanks for your answer,
In fact, chr(256) is equivalent to chr(0) regarding the doc : https://www.php.net/

I've never encountered any problems with these binary content declaration characters (Perhaps VeraPDF is stricter), but it would indeed be a good idea to improve this.

ISO 32000-1:2008, Section 7.5.2 (File Header)

If a PDF file contains binary data, as most do (see 7.2, "Lexical Conventions"), the header line shall be
immediately followed by a comment line containing at least four binary characters—that is, characters whose
codes are 128 or greater. This ensures proper behaviour of file transfer applications that inspect data near the
beginning of a file to determine whether to treat the file’s contents as text or as binary.

I'm submitting a PR.

[benito103e]

Fixed by #41
New release v2.3.1