I don’t really see why #1 is highly unlikely. PDF is very complex, and it’s easily possible that a generator could have a bug.
‘Generally the thing that changed is what broke’
This has been never been true in software engineering. Changed code reveals bugs which need to be fixed elsewhere all the time.
2. Yes, to the end user it looks like a problem with preview.
No, the fact that it opens at all doesn’t make it de facto “valid”.
Yes, handling questionable PDFs is part of writing PDFs handling software.
No, that doesn’t mean that all PDF handling software must or can feasibly handle any and all corruption.
The very fact that there are many kinds of questionably valid PDFs out there proves the point. Handling the the intersection of all the invalid PDFs is impossible.
Rendering correctly has nothing to do with this. PDFs have many attributes which are not rendered.
It really is on the document creator to produce a valid document in the first place.
It’s certainly on ABBYY to have tested this months ago and either fixed it, or publicized it.
‘Generally the thing that changed is what broke’
This has been never been true in software engineering. Changed code reveals bugs which need to be fixed elsewhere all the time.
2. Yes, to the end user it looks like a problem with preview.
No, the fact that it opens at all doesn’t make it de facto “valid”.
Yes, handling questionable PDFs is part of writing PDFs handling software.
No, that doesn’t mean that all PDF handling software must or can feasibly handle any and all corruption.
The very fact that there are many kinds of questionably valid PDFs out there proves the point. Handling the the intersection of all the invalid PDFs is impossible.
Rendering correctly has nothing to do with this. PDFs have many attributes which are not rendered.
It really is on the document creator to produce a valid document in the first place.
It’s certainly on ABBYY to have tested this months ago and either fixed it, or publicized it.