issue displaying signature fields

[ousia]

Having some tests with pdfsig (from poppler), I found issues with Acrobat recognizing signatures in PDF-1.7 documents that veraPDF Arlington validates as documents with no deviations from Arlington PDF model.

signed-parent.pdf gives no problems, since this is a signature parent dictionary and a widget child dictionary, as displayed with Acrobat Reader:¹

The issue comes in signed-child.pdf when the parent field has also a child field by adding /T to the previous widget dictionary, such as in:

2 0 obj
[ 4 0 R ]
endobj

3 0 obj
<<
  /DA (/sstf 11.9552 Tf 1.1955 Ts 0 0 0 rg 0 0 0 RG)
  /FT /Sig
  /Ff 0
  /Kids 2 0 R
  /Q 0
>>
endobj

4 0 obj
<<
  /Type /Annot
  /F 4
  /Parent 3 0 R
  /Subtype /Widget
  /T (Signature)
  /Rect [ 51.908128 44.055269 347.64039 250.58057 ]
  /M (D:20251216082759+01'00')
  /Border [ 0 0 0 ]
  /AP <<
    /N 27 2 R
  >>
  /AS /N
  /V 28 0 R
>>
endobj

Acrobat doesn’t display either the annotation or the signature:

The Arlington validator finds no flaws in signed-child.pdf .

AfaIk, adding a /T entry to the widget child turns it into a terminal field and the signature field and annotation should be displayed as when adding /V to the pure field parent.

Is the validation right or am I missing something here?

Many thanks for your help.

Footnotes

1. The objects read:

   2 0 obj
   [ 4 0 R ]
   endobj
   
   3 0 obj
   <<
     /DA (/sstf 11.9552 Tf 1.1955 Ts 0 0 0 rg 0 0 0 RG)
     /FT /Sig
     /Ff 0
     /Kids 2 0 R
     /Q 0
     /T (Signature)
     /V 28 0 R
   >>
   endobj
   
   4 0 obj
   <<
     /Type /Annot
     /F 4
     /Parent 3 0 R
     /Subtype /Widget
     /Rect [ 51.908128 44.055269 347.64039 250.58057 ]
     /M (D:20251216082344+01'00')
     /Border [ 0 0 0 ]
     /AP <<
       /N 27 2 R
     >>
     /AS /N
   >>
   endobj
   

   ↩

[ousia]

Already dealt with in pdf-association/pdf-issues#714.