Keep /A element when reading PdfOutline

[PetoMPP]

This change updates PdfSharp’s outline and annotation parsing to preserve the /A (Action) dictionary even when a /Dest is also present. Previously, PdfSharp would discard the /A entry when replacing it with a /Dest, which resulted in the loss of important behaviors such as JavaScript execution or chained /Next actions.

In many PDFs — especially those created with Adobe Acrobat or CAD tools — outlines and annotations include compound actions like:

/A <<
  /S /GoTo
  /D [...]
  /Next << /S /JavaScript /JS (...) >>
>>

Discarding the action breaks interactive features such as:

• Highlighting fields (e.g. flashing red rectangles)

• Dynamic form behaviors

• Any action-driven JavaScript logic

Benefits:

• Preserves full PDF behavior and interactivity

• Aligns with the PDF spec, which allows both /A and /Dest

• Enables advanced use cases like viewer development, script analysis, or validation

This change is backward-compatible and improves PdfSharp’s ability to work with professionally authored interactive PDFs.

[ThomasHoevel]

Hi!

Thanks for the information.

Can you provide PDF files for testing, please?

The PDF spec 1.7 writes about the "/A" parameter: "Optional; PDF 1.1; not permitted if a Dest entry is present".
That explains why PDFsharp so far removes the "/A" parameter.

But PDF files in the wild do not always care about the specs.

[PetoMPP]

Hello, I can't really provide this PDF as it contains copyrighted data, but I can show the exact thing from it that I mention in this PR:

6966 0 obj
<</Parent 6965 0 R/A 6967 0 R/Title(REDACTED)/Next 6987 0 R/First 6969 0 R/Last 6969 0 R/Count -1>>
endobj
6967 0 obj
<</Type/Action/S/GoTo/Next 6968 0 R/D[222 0 R/Fit]>>
endobj
6968 0 obj
<</Type/Action/S/JavaScript/JS(highlight\(10, [207.708, 484.866, 344.479, 778.263]\);\n)>>
endobj

As you can see there is both /Next and /D in this /Action, and current implementation converts this /Action into /Dest element, and it is not possible to retrieve the /Next value after the conversion. In this case I need to read the /JS value of where is this Outline pointing to, as the parent is only pointing to /Fit.

[PetoMPP]

I can also provide the code snippet of how I access the data, so it is clearer what is the aim of the changes:

if (!outline.Elements.TryGetValue("/A", out PdfItem actionRef) ||
  pdf.PdfActions.FirstOrDefault(a => a.Reference == actionRef) is not { } action ||
  (action. JavaScript ?? action.Next?.JavaScript) is not { } js)
{
  preciseBounds = false;
  return null;
}

The pdf.PdfActions is just a list of all PdfAction in the PdfDocument created as follows:

document.Internals
  .GetAllObjects()
  .OfType<PdfDictionary>()
  .Where(d => d.Elements.TryGetString("/Type", out string type) && type == "/Action")
  .Select(d => new PdfAction(d))
  .ToArray()

And PdfAction itself is just a small wrapper around PdfDictionary.

public class PdfAction : PdfDictionary
{
  public string Type
  {
    get { return Elements.TryGetString("/S", out string value) ? value : null; }
  }

  public PdfPage DestinationPage
  {
    get
    {
      return Elements.TryGetValue("/D", out PdfItem item) &&
        item is PdfArray destArr &&
        destArr.OfType<PdfReference>().Select(r => r.Value).FirstOrDefault() is PdfPage page
          ? page
          : null;
    }
  }

  public string JavaScript
  {
    get { return Elements.TryGetString("/JS", out string value) ? value : null; }
  }

  public PdfAction Next
  {
    get
    {
      return Elements.TryGetValue("/Next", out PdfItem next) && next is PdfReference nextRef
        ? nextRef.Value as PdfAction
        : null;
    }
  }

  public PdfAction(PdfDictionary dict) : base(dict)
  {
  }
}

[StLange]

Hi!
The upcoming version 6.2.1 fixes this, no elements are removed anymore. As Thomas already wrote, I originally removed the action because of the PDF 1.7 specs. That was wrong and the PDF 2.0 specs was updated.