Adobe Community: Message List - Is a zero length glyf table valid for a TTF subset?

Re: Is a zero length glyf table valid for a TTF subset?

forums_noreply@adobe.com — Fri, 24 Oct 2014 23:58:45 GMT

There are some more details in the link I posted but you can see a PDF here: http://bugs.ghostscript.com/attachment.cgi?id=11252

It happened in CS6 and CC 2014. Basically it happens if you only use invisible characters like space for a TTF font, and .notdef does not exist in the font. It looks like InDesign realises no glyph drawing details are needed so the table is zero length. It seems to be causing a printing failure and various issues with other programs so it sounds like this possibility is not well catered for in many programs, though most recover.

Re: Is a zero length glyf table valid for a TTF subset?

forums_noreply@adobe.com — Fri, 24 Oct 2014 14:23:35 GMT

As far as PDF is concerned, yes this is valid.

Can you tell me what version of InDesign produced these files? Can you post a sample?

Is a zero length glyf table valid for a TTF subset?

forums_noreply@adobe.com — Fri, 24 Oct 2014 06:02:10 GMT

I've posted related queries in a few forums - there is some background info at https://forums.adobe.com/thread/1611899 and it was suggested I ask the experts here

Basically in some situations InDesign is generating a subset font with a zero length glyf table.

Does this 'exists but zero length' table fulfil the criteria from the PDF specification?

The following TrueType tables are always required: “head,” “hhea,” “loca,” “maxp,” “cvt_,” “prep,” “glyf,” “hmtx,” and “fpgm.”

A number of programs are not happy with such files, but Adobe products seem to handle them. However Acrobat in particular is fairly forgiving as we all know.

Microsoft's font validator says the subset is not valid. Programs like Ghostscript attempt to fix it by adding an empty table.