LibreOffice has a syntax error in the PDFs it generates. The /Tabs key of a PDF page object should be a PDF name, not a PDF string. Refer to PDF specification: ISO 32000-2, "Table 31 - Entries in a page object". Problem is caused by code in core/vcl/source/gdi/pdfwriter_impl.cxx at line 753: aLine.append( "/Tabs(S)\n" ); should be: aLine.append( "/Tabs/S\n" ); https://github.com/LibreOffice/core/blob/c84b37c0bbab3b386b22b87be52f965839b44a49/vcl/source/gdi/pdfwriter_impl.cxx
peter.wyatt: just for curiosity, is the spec "ISO 32000-2" available for free and legally somewhere? Indeed, I only found available: https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008.pdf where "Entries in a page object" is table 30 and indicates: "(Optional; PDF 1.5) A name specifying the tab order that shall be used for annotations on the page. The possible values shall be R (row order), C (column order), and S (structure order). See 12.5, "Annotations" for details." Badfully, searching "/Tabs" to try to have an example gives nothing. However, doing some research, I rather see "/Tabs /S" (so with a space between "/Tabs" and "/S", now I don't know if it's important or not. Michael: noticing https://cgit.freedesktop.org/libreoffice/core/commit/?id=fa3f04bdd4f73a1b3be70dfb709c44638ef7e3d9 tdf#148934 PDF/UA export: add Contents entry to Link annotations thought you might have some opinion here.
Yes, the latest ISO 32000-2:2020 specification is available at no-cost for everyone: see https://pdfa.org/sponsored-standards/. This also includes errata and some new cryptographic extensions. Please stop using the ISO 32000-1 spec from way back in 2008! It is very very old, out-of-date, not entirely vendor neutral, and has many known issues that have since been corrected. Regarding needing a SPACE between the key "/Tab" and the value "/S": technically PDF does not need this as "/" is an explicit token delimiter (see sub-clause 7.2.3 Character set). Adding one won't hurt, only that it is unnecessary and will make the resultant PDF file just slightly larger (1 byte for each page). All PDF parsers support the non-whitespace syntax.
I should add the convention in all PDF specs is not to preface PDF name objects with the leading "/" - so just search for "Tabs" (case sensitive, whole words).
Michael Stahl committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/commit/0025190152a35e18c7847e91ad171df339657910 tdf#155228 vcl: PDF export: /Tabs needs PDF name, not string It will be available in 7.6.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Michael Stahl committed a patch related to this issue. It has been pushed to "libreoffice-7-5": https://git.libreoffice.org/core/commit/d93c05579ec9759eca3203ad3608c8f55e1f12b6 tdf#155228 vcl: PDF export: /Tabs needs PDF name, not string It will be available in 7.5.4. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
(In reply to peter.wyatt from comment #2) > Yes, the latest ISO 32000-2:2020 specification is available at no-cost for > everyone: see https://pdfa.org/sponsored-standards/. This also includes > errata and some new cryptographic extensions. I'm just looping in the link trying to download the specs. One time, I got a form to fill with private coordinates but didn't want to respond. I would have expected just a link when clicking on it the download would begin.
If you read the EULA you will understand that all ISO standards are licensed by ISO under per-user conditions. This is "sponsored access" meaning that someone else is generously paying on your behalf - but that cannot/does not change ISO's licensing and copyright.
(In reply to peter.wyatt from comment #7) > If you read the EULA you will understand that all ISO standards are licensed > by ISO under per-user conditions. This is "sponsored access" meaning that > someone else is generously paying on your behalf - but that cannot/does not > change ISO's licensing and copyright. Ok, quite weird for an "open" format.
*** Bug 151826 has been marked as a duplicate of this bug. ***