[Velli20]

Summary

Content inside /OC marked-content sequences was painted no matter what the document's layer settings said. Content in a group listed under the default configuration's /OFF still rendered, which differed from PDFium. Page content now respects optional content.

• Content streams: BDC keeps its property-list name. Resources reads the optional content entries of /Properties. A new OptionalContentFilter in pdf-canvas skips painting and text recording inside sequences whose group or membership is off. It is only created when the document turns some group off, so other documents pay nothing for marked content.
• Renderers: PdfRenderer passes the document's default visibility. The web page renderer passes the annotation overlay's state, so page content and annotations share it.
• New pdf-optional-content crate: the optional content model moves out of pdf-annotation-core because rendering now depends on it. All its decoders are FromPdfObject impls. A single /OCG reference is stored as a one-group /AnyOn membership, which merges the former AnnotationOptionalContent enum into OptionalContentMembership.
• Reader APIs: DictionaryContext::lenient_entries (decode the entries that fit a type, skip the rest) and DictionaryContext::optional_list (one value or an array, nulls skipped).

Notes

• The generated annotation_contract.ts changes: AnnotationOptionalContent is gone, and an annotation's optional_content is now an OptionalContentMembership.
• Not covered yet: an /OC entry on a form or image XObject itself. On the web, page content picks up a SetOCGState change the next time the page is rendered.

Testing

• cargo check --workspace --all-targets, cargo clippy --all --workspace and cargo fmt --check are clean.
• Tests pass for the changed crates. The full cargo test wasn't run locally because the Skia build script downloads prebuilt binaries.
• cargo xtask annotation-types --check passes and cargo xtask web-canvas --profile debug builds.
• cargo conformance render on TCPDF example 024 now matches PDFium: the line in the off layer is hidden, and the line in the on layer and the one in the other layer still show.

🤖 Generated with Claude Code

[github-actions]

Conformance reads

Documents that Safe-PDF reads differently from the base commit, compared with PDFium. A read
regresses when Safe-PDF fails to open a document it opened before, crashes or times out, or
counts a different number of pages than PDFium.

pdf.js corpus

1008 documents compared with 6c723d8: 1 read worse, 0 read better.

Regressions

Document	Base	This pull request
issue19517	read, 1 page	timeout: time limit exceeded (stage safe-read)

840 documents of the PDFium corpus read as on 6c723d8.

Details are in the job summaries of the workflow run. Rerun a case locally with
cargo conformance run --corpus <corpus> --read-only --case <id>.