M5.6: preserve nested annotation values in FDF exports (#1971)

* M5.6: preserve nested annotation values in FDF exports

Copy and renumber retained object graphs without expanding aliases or following
indirect cycles recursively. Refuse excessive work and propagate export errors
before the destination is written. Cover saved geometry, colour and borders,
shared graphs, streams, stale references and refusal through automation tools.

Co-Authored-By: Codex <noreply@openai.com>

* Bound FDF annotation copying before allocation

Keep selected aliases shared, budget retained keys and values before copying, and add direct-payload and alias-count regressions. Retain copied-graph limits and document source-memory scope.

* M5.6: bound FDF cache-eviction discovery and field values

Extend the concurrent annotation-budget correction while retaining its direct-payload and alias regressions. Record annotation positions instead of resolved bodies so cache eviction cannot pin repeated parsed copies; borrow direct values and budget retained entries before cloning. Count every emitted multi-select field value before allocating its output array.

Observed pre-fix allocation-cap and field-limit failures, then fixed tests passed. Final validation: 549 scoped XFDF/engine/automation tests passed, three existing ignored; strict all-targets Clippy, WASM, fmt, layers, assets, parity and diff checks passed.

AI assistance: OpenAI Codex for @MMexicann.

* M5.6: record bounded FDF export regression evidence

Record comment cache-eviction discovery and emitted-field-value budget regressions without changing feature scores or status. Describe copied-graph limits and existing source-parser limits precisely. Final 549 scoped tests, strict Clippy, WASM, fmt, layers, assets and parity passed.

AI assistance: OpenAI Codex for @MMexicann.

* M5.6: align FDF progress with budgeted discovery

Document lazy annotation positions, cache-eviction coverage and copied-graph limits while retaining the original nested-value progress entry and all upstream notes. Estimates unchanged.

AI assistance: OpenAI Codex for @MMexicann.

* M5.6: describe FDF discovery and copied-graph limits

Align exchange documentation with the tested lazy-position discovery implementation and its copied-graph limits. Source parsing/page discovery keep existing limits.

AI assistance: OpenAI Codex for @MMexicann.

* M5.6: align milestone notes with FDF discovery limits

Retain upstream milestone history and describe the tested discovery/copy budgets without increasing estimates or claiming a total source-memory bound.

AI assistance: OpenAI Codex for @MMexicann.

* M5.6: keep nested page links out of FDF exports

Preserve graph aliases and existing budgets; exclude direct and indirect Page/Pages type names. Add saved-PDF regression and bounded type-resolution controls. Both pre-fix failures observed; 46 scoped tests, strict Clippy, WASM and formatting passed.

* M5.6: document bounded nested page exclusion

Address maintainer feedback on the existing PR. Preserve upstream work and document the tested scope and remaining validation limits.

* M5.6: record nested page-reference regression evidence

Address maintainer feedback on the existing PR. Preserve upstream work and document the tested scope and remaining validation limits.

* M5.6: retain FDF limits in milestone evidence

Address maintainer feedback on the existing PR. Preserve upstream work and document the tested scope and remaining validation limits.

* M5.6: cite nested page-reference exclusion tests

Address maintainer feedback on the existing PR. Preserve upstream work and document the tested scope and remaining validation limits.

* M5.6: respect generations while identifying page references

Address maintainer feedback on the existing PR. Preserve upstream work and document tested scope and validation limits.

* XFDF: document stale Type preservation regression

Address maintainer feedback on the existing PR. Preserve upstream work and document tested scope and validation limits.

* M5.6: record generation-aware page exclusion evidence

Address maintainer feedback on the existing PR. Preserve upstream work and document tested scope and validation limits.

* M5.6: propagate FDF export errors in usage example

Address maintainer feedback on the existing PR. Preserve upstream work and document tested scope and validation limits.

* M5.6: consolidate roadmap change and target fields

Address maintainer feedback on the existing PR. Preserve upstream work and document tested scope and validation limits.

---------

Co-authored-by: Codex <noreply@openai.com>
Co-authored-by: skylar taylor-barrick <hi@skylar.cc>

parity/acrobat-features.toml

@@ -4160,8 +4160,8 @@ milestone = "M5"
 status = "shipped"
 commands = ["comment.export"]
 tools = ["doc_export_data"]
-evidence = ["crates/xfdf/src/tests.rs::xfdf_round_trips_comments_and_values", "crates/xfdf/src/tests.rs::fdf_round_trips_values_and_comments", "crates/automation/tests/automation.rs::comments_and_form_data_travel_as_xfdf_fdf_and_text", "crates/xfdf/src/tests.rs::xfdf_exports_preserve_whitespace_in_comment_attributes"]
-notes = "XFDF exports retain tabs and line breaks in comment identities and metadata."
+evidence = ["crates/xfdf/src/tests.rs::fdf_export_nulls_nested_page_links_without_copying_the_source_page_tree", "crates/xfdf/src/tests.rs::fdf_export_bounds_indirect_type_alias_lookups", "crates/xfdf/src/tests.rs::fdf_export_preserves_metadata_with_stale_type_references", "crates/xfdf/src/tests.rs::fdf_export_keeps_indirect_values_nested_in_annotation_properties", "crates/xfdf/src/tests.rs::fdf_export_preserves_shared_cycles_and_nested_streams_without_expansion", "crates/xfdf/src/tests.rs::fdf_export_refuses_excessive_direct_depth_values_and_payload", "crates/xfdf/src/tests.rs::fdf_export_refuses_aliases_before_cloning_large_annotation_values", "crates/xfdf/src/tests.rs::fdf_export_refuses_repeated_saved_annotations_after_cache_eviction", "crates/automation/tests/automation.rs::fdf_nested_comment_values_survive_export_import_and_save_through_tools", "crates/automation/tests/automation.rs::refused_fdf_export_keeps_the_destination_and_source_through_tools", "crates/xfdf/src/tests.rs::xfdf_round_trips_comments_and_values", "crates/xfdf/src/tests.rs::fdf_round_trips_values_and_comments", "crates/automation/tests/automation.rs::comments_and_form_data_travel_as_xfdf_fdf_and_text", "crates/xfdf/src/tests.rs::xfdf_exports_preserve_whitespace_in_comment_attributes"]
+notes = "FDF preserves shared/cyclic nested values. Discovery keeps lazy array owners and annotation positions; retained entries are budgeted before cloning, including after saved-PDF cache eviction. Copied-graph limits are 100,000 comments/objects/values, 64 direct levels and a conservative 64 MiB data budget; refusal precedes writing. Source parsing and page discovery retain existing COS/parser limits, with no total source-memory bound. Source /Page and /Pages dictionaries become null at every copy depth; indirect Type names check each reference generation with iterative cycle detection and a 64-reference limit; stale Type references preserve unrelated metadata; a saved/reopened three-page fixture verifies small output and retained unrelated metadata. Appearances and source-document links are not carried; FDF import semantics are unchanged. XFDF exports retain tabs and line breaks in comment identities and metadata."
 
 [[feature]]
 id = "comment.export-selected"
@@ -4692,8 +4692,8 @@ milestone = "M6"
 status = "shipped"
 commands = ["form.export_data"]
 tools = ["doc_export_data"]
-evidence = ["crates/xfdf/src/tests.rs::xfdf_round_trips_comments_and_values", "crates/automation/tests/automation.rs::comments_and_form_data_travel_as_xfdf_fdf_and_text", "crates/xfdf/src/tests.rs::xml_exports_preserve_whitespace_in_field_names"]
-notes = "XFDF, FDF; XFA forms also export their data as XML or XDP (form.xfa-data); XML/XFDF exports retain tabs and line breaks in field identities through character references."
+evidence = ["crates/xfdf/src/tests.rs::fdf_export_counts_emitted_field_values_before_allocating_lists", "crates/xfdf/src/tests.rs::xfdf_round_trips_comments_and_values", "crates/automation/tests/automation.rs::comments_and_form_data_travel_as_xfdf_fdf_and_text", "crates/xfdf/src/tests.rs::xml_exports_preserve_whitespace_in_field_names"]
+notes = "XFDF, FDF; FDF counts emitted field values, including every multi-select list entry, before allocating the output list and refuses exports beyond its shared 100,000-value budget. Existing source-field parsing limits remain unchanged. XFA forms also export their data as XML or XDP (form.xfa-data). XML/XFDF exports retain tabs and line breaks in field identities through character references."
 
 [[feature]]
 id = "form.data-xml-csv-txt"