feat: EPDF_RemoveOptionalContentGroups — hidden optional-content layer removal (follow-up to #673)#28
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Phauks wants to merge 2 commits into
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feat: EPDF_RemoveOptionalContentGroups — hidden optional-content layer removal (follow-up to #673)#28Phauks wants to merge 2 commits into
Phauks wants to merge 2 commits into
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Add three EmbedPDF extension functions for redaction-defensibility scrubbing of non-content hidden vectors, mirroring the existing EPDF_SetMetaText style: - EPDF_RemoveXMPMetadata: drop the catalog /Metadata XMP stream (survives an Info-dict clear — the embedpdf#1 sanitization miss). - EPDF_RemoveEmbeddedThumbnails: drop every page /Thumb. - EPDF_RemoveAllJavaScript: drop /Names /JavaScript, JS /OpenAction, and /AA. Declared in public/fpdf_doc.h (auto-exported by the WASM build's generator), implemented in fpdfsdk/fpdf_doc.cpp via GetMutableRoot()/RemoveFor.
…t layers Per-page, drop page objects not visible under the default (View) OC config (CPDF_OCContext::CheckPageObjectVisible resolves OCG/OCMD/VE), regenerate the content, then remove the catalog /OCProperties. Excises hidden-layer content rather than just deleting /OCProperties (which would reveal it). Declared in public/fpdf_doc.h, implemented in fpdfsdk/fpdf_editpage.cpp (reuses FPDF_LoadPage for content parsing + CPDF_PageContentGenerator for regen).
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Follow-up to embedpdf/embed-pdf-viewer#673 — adds the fourth, harder sanitization vector: removing content hidden behind OFF optional-content groups (layers).
Stacked on #27 (the XMP/JS/thumbnails exports). This branch includes #27's commit; the OCG-specific commit is
8b8a678. Please land #27 first — I'll rebase this onto the merged base so it shows only the OCG change.EPDF_RemoveOptionalContentGroups(doc)Hidden layers can't be sanitized by just deleting
/OCProperties— that would make the hidden content visible. This excises the content instead: for each page it drops the page objects that are not visible under the default (View) configuration (usingCPDF_OCContext::CheckPageObjectVisible, which resolves OCGs, OCMDs, and/VEvisibility expressions), regenerates the page content, then removes the catalog/OCProperties. Implemented infpdfsdk/fpdf_editpage.cpp(reusesFPDF_LoadPagefor content parsing andCPDF_PageContentGeneratorfor regeneration), declared inpublic/fpdf_doc.h.The TypeScript
optionalContentGroupsflag onsanitizeDocumentand a test (test-remove-ocg.mjs: hidden-layer text removed via text extraction,/OCPropertiesgone, visible content preserved) are in the companion monorepo PR.Known scope / follow-ups (noted for review): this covers page-level content marked by hidden OCGs. Content inside form XObjects with their own
/OC, annotation/OC, and deeply nested cases may need additional handling or a rasterize-flatten fallback — happy to extend based on your preference.