Major Description
In an effort to keep file sizes small, we leverage Font Subsets in our PDFs.
Also, we already have "incremental change and signing" (where fields are changed after a signature, without voiding the prior signature thanks to using `saveIncremental` and signing the changes) working just fine in most cases.
However, when the Font on a field is changed or a new Font Subset must be added to the document because the characters used in a field with a tightly-subsetted Font, things don't work correctly:
- The signatures stay valid, which is great
- But the new Font information does not appear to get written to new version appendix, so you get nonsense rendering in a PDF viewer since the field still points to a Font resource that is either not there or is a subset that does not contain all the necessary characters. I'm not super proficient in this so I don't know exactly what's going on.
I have ensured that the fields we update are getting marked as `setNeedToBeUpdated(true)` (this is, I believe, why the fields changes do end up in the version changes), it just seems that the Font resources are not getting updated in the version.
I have also tried to mark the document's PDResource as `setNeedToBeUpdated(true)` but to no avail.
Is this behavior possible/allowed? Is it a bug or am I doing something wrong?
I have included an example file where the field named `incrementalChangeField` goes from `NotoSans-Regular` to `NotoSansCJK-Regular` during the incremental change, but the font resource does not get added.
Thanks for your time!
