Bug #18932
Updated by Jan Haller 20 days ago
qpdf previously failed to merge identical files, if they contained references. This issue has been resolved by qpdf (https://github.com/qpdf/qpdf/issues/272).
pdfunite had problems when merging certain PDFs generated by wkhtml/qfqpdf with other certain PDFs which then could not be opened by the Chrome Extension "Adobe Acrobat". Suspected cause for this behavior is a xref issue.
For more details check #18847