Pon not updated in getOutGradientShaders

[mklemarczyk]

Pon need to be updated before exiting the method, otherwise getObjectNumber can return old pon value.

[CLAassistant]

All committers have signed the CLA.

[coveralls]

Coverage remained the same at 100.0% when pulling c3aee8a on mklemarczyk:develop into 9b649b1 on tecnickcom:develop.

[nicolaasuni]

The "pon" is intentionally not updated if the document is PDF/A or there are no gradients.
Do you have a test or a specific case that explains why this has to be changed?

[mklemarczyk]

I created script like this:

$pdf = new Tcpdf();
$pdf->page->add();
$pdf->setFont('pdfacourier'); // method adds new font to stack / I can pull request it, but it is not finished yet
echo $pdf->getOutPDFString();

In output printed the PON number is duplicated for objects after graph.

In Output.php:

        $out .= $this->graph->getOutGradientShaders($this->pon); // pon is correct when goes into method
        $this->pon = $this->graph->getObjectNumber(); // pon is set to value lower than it was before, which causes a problem with PON duplication

So if you say it should not be updated, therefore I can suggest two other solutions different than this one.

1. Do not reassign the pon from method $this->graph->getObjectNumber() in the same case what the pon is not updated in getOutGradientShaders
2. Set a higher number max(oldPon, getObjectNumber), therefore it will always get higher numer.