Fixed: Font subsetting - incorrect placement of head checksum #849
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…ting head offset.
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williamdes
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Feb 2, 2026
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williamdes
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williamdes
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Can you provide a before and after pdf please?
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Yes, here: Using code like this: $pdf = new \TCPDF();
$pdf->AddFont('Unifont', '', PDF_FONTPATH . 'unifont.php', true);
$pdf->setFont('Unifont', '', 16);
$pdf->AddPage();
$pdf->Write(16, "ABC");
$pdf->Output('out.pdf', 'D');(I am using TCPDF 6.4.4, but the problem is probably the same in current.) |
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Thanks |
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Currently, during font subsetting, head checksum is calculated and placed on offset 8 after head table start,
but this is incorrect and causes overwriting head.offset field!
The checksum should be placed in offset 4 after the tag 'head'.
This PR fixes this.
For me, this fixed PDF display error on Adobe Reader and or not diplaying proper characters in Edge PDF viewer.