Error while creating a deep clone of decrypted PDFDocument object.

[Talha345]

What were you trying to do?

I create a deep clone of the PDFDocument object before applying any changes to it using the following code:

const copiedPdfDoc = await PDFDocument.load(await pdfDoc.save());

This approach has been working reliably for a long time, but after switching to the new fork, I've encountered a problem with certain encrypted PDF files that have been decrypted. For most files, the deep clone works fine. However, when dealing with specific decrypted PDFs, the PDFDocument.catalog in the cloned document is set to PDFInvalidObject instead of the expected PDFCatalog and when I try to do await copiedPdfDoc.save();, I get the following error:

TypeError: this.catalog.Pages is not a function
    at PDFDocument.computePages [as populate] 
    at Cache.access (Cache.js:11:1)
    at PDFDocument.getPages (PDFDocument.js:478:1)
    at PDFDocument.getPageCount (PDFDocument.js:462:1)
    at PDFDocument.save (PDFDocument.js:1147:1)

Document for which the issue occurs:

g-1145.pdf

How did you attempt to do it?

1. Load the provided PDF document.
2. Create a deep clone of the document using the code provided above.
3. Try to save the copied pdf document.

What actually happened?

TypeError: this.catalog.Pages is not a function
    at PDFDocument.computePages [as populate] 
    at Cache.access (Cache.js:11:1)
    at PDFDocument.getPages (PDFDocument.js:478:1)
    at PDFDocument.getPageCount (PDFDocument.js:462:1)
    at PDFDocument.save (PDFDocument.js:1147:1)

What did you expect to happen?

The PDF to be saved properly.

How can we reproduce the issue?

Use the steps above.

Version

2.2.3

What environment are you running pdf-lib in?

Browser

Checklist

• My report includes a Short, Self Contained, Correct (Compilable) Example.
• I have attached all PDFs, images, and other files needed to run my SSCCE.

Additional Notes

After further investigation, it looks like the file gets corrupted upon saving and therefore can't be loaded again correctly even in other PDF viewers. I am using decrypting the file with '' as password in the first place.

[Talha345]

Update: I migrated the decryption logic to use qpdf CLI on the BE and it works like a charm but it would be nice if pdf-lib handles this correctly.

[Sharcoux]

We might try to have a look, but I'm really not sure we can help on this. I'll mark this as help wanted.