FB16384138: Markup generates annotations with broken appearance streams in certain PDF

[douglashill]

Date: 2025-01-22
Resolution: Open

(Attachments not included here for confidentially.)

Basic Information

Please provide a descriptive title for your feedback:
Markup generates annotations with broken appearance streams in certain PDF

Which area are you seeing an issue with?
Files app

What type of feedback are you reporting?
Incorrect/Unexpected Behaviour

Details

What does the Files issue you are experiencing involve?
Using Markup to edit a document

When you see this issue, where are the files located you are using?
Something else not on this list

Description

Please describe the issue and what steps we can take to reproduce it:

Steps:

1. Add the attached PDF file [REDACTED] so it’s accessible from the Files app on an iPad or iPhone.
2. Open the Files app and navigate to this document
3. Tap the document to open it. The window that appears may flicker and eventually only display a placeholder instead of showing the document contents. If this happens press Done and try re-opening the document again until it renders successfully.
4. Use a pen tool to draw on the document. E.g. writing “hello” on the first page.
5. Tap Done to close the document.
6. Send the edited document to a Mac.
7. Open the edited document in Adobe Acrobat on macOS or any other non-Apple PDF reading software, such as our own PDF Viewer (https://apps.apple.com/app/id1120099014)

See a screen recording of steps 2–5 attached as “Add drawing using Markup.mp4”.

Expected:

The drawing added to the document should appear in Acrobat or other readers similar to how it appeared in Markup.

Observed:

The drawing added to the document appears as a placeholder box or similar (depending on the PDF reader used).

See a screenshot attached as “Result in Acrobat.png”.

Configuration:

I’m using a 13-inch iPad Pro (M4) with 1 TB of storage running iOS 18.2.1.

Tested with the file stored in both On my iPad and iCloud Drive.

Notes:

Since Markup writes annotation data in a proprietary format under the AAPL:AKExtras key in the annotation dictionary, non-Apple PDF readers rely on an appearance stream to render annotations created by Markup.

However the normal appearance stream of the added annotation (AP > N in the annotation dictionary) is a reference to object number 0, which doesn’t exist.

This issue doesn’t happen with simpler PDF files. The appearance stream is written correctly with such files so they can be displayed correctly by non-Apple PDF readers.