Outline Iterator Object "open" property not applied after insertion

[King-of-Infinite-Space]

Hi devs, I want to add outlines that by default show first two levels and fold sub-levels.

I noticed two issues:

1. After inserting the outline item, property open always prints false.
2. Despite what is set and what is printed, the saved file always have all outlines unfolded.

const outlineIterator = doc.outlineIterator()

outlineIterator.insert({
  title: '1',
  open: true,
  uri: doc.formatLinkURI({
    page: 1,
    type: 'XYZ'
  }),
})

outlineIterator.prev()
console.log(outlineIterator.item())
// always prints "open: false"

outlineIterator.down()

outlineIterator.insert({
  title: '1.1',
  open: false,
  uri: doc.formatLinkURI({
    page: 1,
    type: 'XYZ'
  }),
})

outlineIterator.prev()
console.log(outlineIterator.item())

outlineIterator.down()

outlineIterator.insert({
  title: '1.1.1',
  open: false,
  uri: doc.formatLinkURI({
    page: 1,
    type: 'XYZ'
  }),
})

fs.writeFileSync('output.pdf', doc.saveToBuffer().asUint8Array())
const doc_output = mupdf.Document.openDocument(fs.readFileSync('output.pdf'), 'application/pdf')
for (const item of doc_output.loadOutline()) {
  console.log(item)
  // for all foldable items, open: true 
}

[King-of-Infinite-Space]

The above point 1 can be ignored as I understand how PDF stores an outline item.

I think point 2 is due to an upstream issue in do_outline_update in pdf-outline.c
When an outline item is inserted, the open property is not being applied, and count always increment, resulting in all outline levels being unfolded.

The workaround is to do another pass to update the items after insertion, so that open is correctly applied.

[jamie-lemon]

@King-of-Infinite-Space Thanks for this - as this is an upstream issue (i.e. to do with core mupdf) would you mind reporting this bug here: https://bugs.ghostscript.com/ ? (feel free to tag this Issue on the bug and vice-versa)

[King-of-Infinite-Space]

reported upstream Bug 707878