* extractor: drop Latin-1 mojibake on Type0/CID fonts; tokenize wide TSR items
Two text-extraction failure modes surfaced by table-candidate shadow
data; both also affect the existing TableFormer / vector-grid paths
since they share `extract_tables_with_structure_*_mem`'s downstream
cell-fill.
1. CJK / multi-byte mojibake. The bottom Latin-1 fallback in
`extract_text_from_operand` ran unconditionally. For a Type0/CID
(Identity-H) font whose ToUnicode CMap fails to parse, the bytes
are CIDs (font-internal indices), not character codes — per-byte
Latin-1 produces mojibake (e.g. 2-byte CID 0xCDD9 surfaces as "ÍÙ").
Gate that fallback on `FontWidthInfo.is_cid` (set by
`parse_type0_widths` for `/Subtype /Type0`). For Type0 fonts with
any non-ASCII byte, emit one U+FFFD per CID instead so
`detect_encoding_issues` still trips and the page is flagged for
OCR — preserving the existing OCR-routing path that the
high-Latin-1 garbage used to satisfy by accident. Type1 / TrueType
simple fonts retain the per-byte Latin-1 round-trip (it IS the
canonical interpretation for them; verified against an existing
pdf-evals fixture where bytes like 0xB6 are legitimate Latin-1).
Threaded `font_widths: &PageFontWidths` through
`extract_text_from_operand` and its 5 call sites in
`content_stream.rs` / `xobjects.rs`.
2. Dense-cell text collapse in `extract_tables_with_structure_cells_mem`.
Stage-1 routing did per-item assignment — each TextItem went into the
single cell whose bbox contained its center. When a row's text is
rendered as one wide Tj (e.g. "Marshall Islands 0.9 0.9 0.9"), the
whole row parks in one cell and the rest of the row stays empty.
New `split_item_into_token_subitems` helper splits each item into
per-token virtual sub-items with x positions estimated from
`effective_width / char_count` and the token's character offset.
Stage 1 then routes per-token. Single-token items collapse to a
one-element vector (no behavior change). Multi-token items spanning
multiple cells distribute correctly. Stage-2 orphan recovery now
operates on token-grain orphans rather than re-trying whole items.
Tests:
- `cid_font_with_unparseable_cmap_does_not_emit_latin1_mojibake` (unit)
exercises the Type0/CID + unparseable-CMap fallback path.
- `simple_font_latin1_fallback_passes_high_bytes_through` (unit)
guards the false-positive case where a Type1 font's `/ToUnicode`
reference is set but bytes are legitimate Latin-1 character codes.
- `test_extract_tables_with_structure_distributes_wide_item_across_cells`
(integration) builds a synthetic PDF with one wide Tj and asserts
each token lands in its own cell.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* tests: pin CID mojibake fix mechanism with FFFD assertions
Two complementary tests for the Type0/CID Latin-1-fallback guard:
1. Tighten `test_identity_h_no_tounicode_suppresses_garbage` on the
existing real-PDF fixture `shinagawa_identity_h.pdf` to also assert
the pre-suppression text contains U+FFFD and contains no high-Latin-1
chars. Pins down WHICH mechanism is suppressing the garbage so a
future regression that re-enables Latin-1 mojibake fails loudly here
instead of silently switching the suppression chain back to
`is_cid_garbage` + high-Latin-1 detection.
2. Add `test_synthetic_type0_broken_tounicode_emits_fffd_not_latin1_mojibake`
with a fully-synthetic Type0 / Identity-H PDF built in process. We
control the malformed ToUnicode contents, the descendant CIDFontType2
shape (just enough for `parse_type0_widths` to set `is_cid=true`,
which is what the new guard keys off of), and the Tj byte stream.
No fixture file or external license needed. Reproduces the exact
"Type0 + non-ASCII bytes + unparseable ToUnicode" code path that
produced the production mojibake samples.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Abimael MartellandClaude Opus 4.7
cfc080f79a