[yilmazhasan]

Fixes #353

Some generators draw every table rule as a thin filled rectangle instead of a stroke. Those slivers are too small for rect clustering and never reach line-based detection, so the table falls to the heuristic pass and its rows and columns come out broken.

Changes

• Hairline fills → rules (synthesize_lines_from_thin_rects): thin fills become line segments for the line-based pass, with per-cell slivers welded into rules. It only returns lines when they form a grid (≥3 horizontal and ≥2 vertical rules of table length). Stray underlines can't fabricate a table, and horizontal-only layouts keep their per-cell segment endpoints for the existing thin-rect fallback.
• Page rules aren't row edges: horizontals more than one row pitch outside the vertical rules' span (running-header and footer rules, note boxes) are ignored. Rules just past the span, like a header rule above partial-height verticals, still count.
• Runs crossing a column rule are cut: when a drawn vertical rule crosses a run's baseline, the run is cut at the nearest word space. This handles two cells painted so close that extraction merges them ("…corpuscular MCHC"). The cut is limited to the line-based path and to drawn rules. Fragments map back to their item index once.
• Rotated row-group labels: a rotated label that sits wholly inside the grid goes into the merged cell its column's rules describe. Labels that cross a ruled interior row edge are rejected.
• Row-group entries stay separate rows: in a table whose first column is mostly empty, a row that fills the same columns as the entry above is not merged on either continuation path. Wrapped tails still merge.

Review feedback addressed

• The old double-space split in assign_items_to_grid was removed. It depended on an extraction quirk that fix(extractor): keep word spaces painted as squeezed whitespace runs #517 removed, and it also applied to inferred column edges. It's replaced by the rule-crossing cut above, so detect_rects.rs is unchanged.
• Duplicate item_indices from split runs are fixed: fragments are deduplicated back to one original index.
• Weld clustering: segments are grouped by coordinate first, then welded in axis order, so near-collinear runs can't interleave.
• Row-group heuristic: the empty-first-cell count skips blank and footnote rows, the lowercase check looks only at the entry label (lowercase values like yes are fine), and the guard covers is_wrapped_continuation too.
• Tests: fixtures renamed to describe what they cover. There is one test_snapshot_* per fixture with accurate doc comments, the order assertion compares positions, and the redundant prefix check is gone. Unit tests were added for the row-group heuristic (positive and wrapped-tail negative), the run split, synthesis welding, the grid gate, and the weld.

Second round:

• Ruled-span slack uses the median rule gap, not the largest, so one tall merged row can't re-admit page furniture.
• The rule-crossing test uses the run's baseline instead of its box midpoint, and only applies to level runs. Oblique runs are left whole.
• Row-group detection also covers a three-row group with two blank first cells. Larger tables keep the 3/4 ratio, because a 2/3 ratio also matched nexo-price-en, whose blank-first-cell rows are wrapped tails.
• Two-column row-group entries stay separate rows: one filled entry cell is enough, and lowercase wrapped tails still merge.

Not changed: the trailing 1-3 chapter-page footer in the second snapshot. Stripping N-N lines is a separate postprocess change, and a standalone range like that is ambiguous, so I'd rather not fold it into this PR.

Verification

• cargo fmt, cargo clippy -- -D warnings and cargo test pass.
• Output on all 46 fixture PDFs was compared against main. Besides the two new fixtures, only td9264 changes: in its three-column cross-reference table (section / remove / add), four references that were merged into one cell now get one row each, as they appear in the PDF. That table's other two columns are still lost, as on main.
• pdf-evals (bench.py test) has not been run yet; it isn't available in my environment.

🤖 Generated with Claude Code

[cubic-dev-ai]

1 issue found across 5 files

Confidence score: 3/5

• In src/tables/detect_rects.rs, a split run can add the same original index more than once to a cell, so callers may see duplicate items. Keep item_indices unique per cell.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. When an issue isn't valid or won't be fixed in this PR, reply in its thread with the reason and then resolve the thread. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/tables/detect_rects.rs">

<violation number="1" location="src/tables/detect_rects.rs:1862">
P2: A split run now contributes its original index `idx` once per fragment that lands in a cell, so `item_indices` can hold the same index multiple times. `assign_items_to_grid`'s contract says it returns "the original item indices that were consumed", and the rect-path callers (e.g. lines 1679, 2321, 3316, 3629) build `Table::new(..., item_indices)` straight from this list without dedup, unlike the detect_lines callers which dedup at lines 1037-1038. Duplicate entries inflate `item_indices.len()`, which is used as positive evidence in `table_evidence_score` (detect_lines.rs:1086, `item_indices.len() * 100`) and as a tie-breaker (line 1097), so one split run can over-count a table's claimed items. Push `idx` into `indices` only once per split run (e.g. track whether any fragment of the run was placed, then push once).</violation>
</file>

<sub>Shadow auto-approve: would not auto-approve because issues were found.
Tip: instead of fixing issues one by one fix them all with cubic

Re-trigger cubic</sub>

[cubic-dev-ai]

1 issue found across 5 files (changes from recent commits).

Confidence score: 5/5

• The comments in tests/integration_tests.rs say these tests check table headers, but they assert data rows instead. Update the comments to match what the tests cover.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. When an issue isn't valid or won't be fixed in this PR, reply in its thread with the reason and then resolve the thread. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="tests/integration_tests.rs">

<violation number="1" location="tests/integration_tests.rs:1360">
P3: The doc comment on `test_custom_table_first_row` and `test_body_before_table` says "Whether the table header is rendered correctly", but neither tests a table header: the first asserts a data row and the second asserts a body paragraph before the table. This was copy-pasted from `test_custom_table_header` and misleads readers about what each test guards. Give each test a doc comment that matches what it asserts.</violation>
</file>

<sub>Shadow auto-approve: would not auto-approve because issues were found.

Fix all with cubic | Re-trigger cubic</sub>

[devin-ai-integration]

Devin Review found 4 potential issues.

2 flags not posted on this PR by your GitHub settings — view them in Devin Review. (Configure)

[cubic-dev-ai]

All reported issues were addressed across 10 files

<sub>Shadow auto-approve: would not auto-approve because issues were found.
Reply to a comment to ask cubic a question or push back. It learns from your replies.
Click Fix with cubic on a comment, or reply @cubic-dev-ai fix this, and cubic writes the fix.

View guided diff | Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 9 files

<sub>Shadow auto-approve: would not auto-approve because issues were found.

View guided diff | Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 3 files (changes from recent commits).

<sub>Shadow auto-approve: would not auto-approve because issues were found.
Tip: Review your code locally with the cubic CLI to iterate faster.

View guided diff | Re-trigger cubic</sub>

[cubic-dev-ai]

0 issues found across 1 file (changes from recent commits).

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

<sub>Shadow auto-approve: would require human review. Hairline-fill rule synthesis, row-group label placement, run splitting, and row-merge heuristics with snapshots/tests. Unresolved dismissed findings on rotated-label capture, endpoint preservation, duplicate indices, and a stray footer require human sign-off.

View guided diff | Re-trigger cubic</sub>