M6: distinguish CSV header tabs from TSV delimiters

ROADMAP.md

@@ -2,7 +2,7 @@
 
 **Stage: alpha** · next: beta, ~25% (ready for real work 50% → 75%) and ~400–700 h away
 
-> **Last reviewed:** 2026-10-15 · **Last updated:** 2026-10-15 · **Change:** minor (M2/gap 12: the Annex D.2 alias codes read as the ink they draw in both tables; the text oracle scores reading order; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
+> **Last reviewed:** 2026-10-15 · **Last updated:** 2026-10-15 · **Change:** minor (M6: CSV tab-containing headers; estimates unchanged)
 > **Last reviewed:** 2026-10-13 · **Last updated:** 2026-10-14 · **Change:** minor (M14: the Italian catalog has every entry the other catalogs had and the code looks up; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
 > **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-14 · **Change:** minor (M3 #2080 candidate: explicit search jumps join per-tab history; rail and control-channel Back/Forward; estimates unchanged)
 > **Last reviewed:** 2026-10-13 · **Last updated:** 2026-10-13 · **Change:** minor (M4 #1910: Organize Pages opens on the current page; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
@@ -157,6 +157,7 @@ Ranked; detail and the full milestone table in [docs/roadmap.md](docs/roadmap.md
 | 8 | 1.0 polish: performance, right-to-left, missing languages, keyboard-only (M14) | 55–95 |
 
 ## Progress log
+- **2026-10-15 (M6, CSV tab-containing headers):** CSV export and spreadsheet merging quote tabs, and import distinguishes quoted tabs from TSV delimiters without changing field identities. Synthetic export/import and incremental/full save regressions cover header tabs, quotes and line breaks, plus ordinary TSV controls. Formula-cell policy is unchanged. Estimates unchanged.
 - **2026-10-15 (M2, gap 12):** `cargo xtask text-oracle` scores reading order as well as word F1: the longest common subsequence of the two word sequences over the longer one. F1 is a bag of words and cannot see order at all -- measuring #2431, a change that moves text and nothing else, it called 26 of the 29 files whose output changed identical, where the order score separated 18 improvements from 6 regressions. Reports, does not gate; a disagreement with Poppler, not a verdict. Estimates unchanged.
 - **2026-10-15 (M2, #2305 follow-up):** WinAnsiEncoding 0xA0 and 0xAD and MacRomanEncoding 0xCA extract as the ordinary space and hyphen Annex D.2 names them, in the vendored hayro tables (patch 30) as well as `crates/fonts`, so search, copy and redaction see characters that were hidden behind U+00A0 and U+00AD. Across the pdf.js corpus the soft hyphens we extract fall 117 to 13 and the non-breaking spaces 30 to 26; the rest come from `/ToUnicode`. An explicit `/Differences` name keeps its glyph list value, as pdftotext does. Estimates unchanged.
 - **2026-10-13 (community, M3, #1569 review):** Pixel-only Wayland wheel, wheel-tilt and continuous input use standalone moved events, so Ctrl zoom does not remain latched after the modifier is released (#991); vendored winit patch (13), with a policy test. Estimates unchanged.
@@ -493,6 +494,7 @@ Newest first: the date, what moved, and the new overall estimate.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-15 | minor | M6: CSV export and spreadsheet merging quote tabs, and import distinguishes quoted tabs from TSV delimiters without changing field identities. Estimates unchanged. |
 | 2026-10-12 | minor | M6: valid AcroForm XML element names with original PDF field names preserved; saved-PDF collision and Unicode regressions. Estimates unchanged. |
 | 2026-10-12 | minor | M6: preserve carriage returns in exported CSV field names and values; saved-PDF round-trip coverage. Estimates unchanged. |
 | 2026-10-13 | minor | M4: Insert-from-file preserves source bookmarks; integration tests retained with current main. Estimates unchanged. |

crates/xfdf/README.md

@@ -18,6 +18,10 @@ let report = import(&mut doc, &bytes)?;                 // XFDF, FDF, XML, CSV o
 - **Form data**: Acrobat's XML (`xfdf:original` keeps names that aren't XML names), CSV and
   tab-delimited text (a row of names, a row of values).
 
+CSV export and spreadsheet merging quote tabs, and import distinguishes quoted tabs from TSV
+delimiters without changing field identities. Automatic detection of externally authored, ambiguous
+tables remains heuristic. Formula-cell policy and tab-delimited export are unchanged.
+
 Import replaces comments with the same `/NM` (and drops the replaced comment's pop-up), draws
 appearances PdfCraft can draw, and sets values through the form's own checks (formats,
 validation, recalculation); read-only fields take imported values, as in Acrobat. XML is read

crates/xfdf/src/lib.rs

@@ -612,7 +612,7 @@ pub fn export_data(doc: &Document, format: Format) -> String {
             out
         }
         Format::Csv => {
-            let q = |s: &str| if s.contains([',', '"', '\n', '\r']) { format!("\"{}\"", s.replace('"', "\"\"")) } else { s.to_string() };
+            let q = |s: &str| if s.contains([',', '"', '\n', '\r', '\t']) { format!("\"{}\"", s.replace('"', "\"\"")) } else { s.to_string() };
             format!(
                 "{}\n{}\n",
                 fields.iter().map(|f| q(&f.0)).collect::<Vec<_>>().join(","),
@@ -1041,7 +1041,7 @@ pub fn merge_csv(files: &[Vec<(String, Vec<String>)>]) -> String {
             }
         }
     }
-    let q = |s: &str| if s.contains([',', '"', '\n', '\r']) { format!("\"{}\"", s.replace('"', "\"\"")) } else { s.to_string() };
+    let q = |s: &str| if s.contains([',', '"', '\n', '\r', '\t']) { format!("\"{}\"", s.replace('"', "\"\"")) } else { s.to_string() };
     let mut out = columns.iter().map(|c| q(c)).collect::<Vec<_>>().join(",");
     out.push('\n');
     for f in files {
@@ -1101,6 +1101,31 @@ fn import_fdf(doc: &mut Document, bytes: &[u8]) -> Result<Report, DataError> {
     Ok(report)
 }
 
+// Inspect the first logical record: tabs within quoted CSV cells are data. A quote
+// in the middle of an unquoted TSV name stays literal, as in the TSV reader.
+fn has_tab_delimiter(text: &str) -> bool {
+    let mut quoted = false;
+    let mut cell_start = true;
+    let mut chars = text.chars().peekable();
+    while let Some(c) = chars.next() {
+        match c {
+            '"' if quoted && chars.peek() == Some(&'"') => {
+                chars.next();
+            }
+            '"' if quoted || cell_start => {
+                quoted = !quoted;
+                cell_start = false;
+            }
+            '\t' if !quoted => return true,
+            '\r' | '\n' if !quoted => return false,
+            ',' if !quoted => cell_start = true,
+            _ => cell_start = false,
+        }
+    }
+    // An unclosed quote can be a literal TSV field-name character.
+    quoted && text.lines().next().is_some_and(|line| line.contains('\t'))
+}
+
 /// Form data from XML, CSV or tab-delimited text.
 fn import_table(doc: &mut Document, text: &str) -> Result<Report, DataError> {
     let mut report = Report::default();
@@ -1117,7 +1142,7 @@ fn import_table(doc: &mut Document, text: &str) -> Result<Report, DataError> {
                 (name, vec![c.text().unwrap_or("").to_string()])
             })
             .collect()
-    } else if t.lines().next().is_some_and(|l| l.contains('\t')) {
+    } else if has_tab_delimiter(t) {
         tab_delimited(t)?
     } else {
         // CSV with quotes: a quoted value may hold commas, doubled quotes and line breaks.

crates/xfdf/src/tests.rs

@@ -1011,3 +1011,49 @@ fn xfdf_import_keeps_text_around_xml_comments_and_instructions() {
         assert_eq!(values(&reopened)[0].1, want, "{xml_text}");
     }
 }
+
+#[test]
+fn csv_headers_with_tabs_survive_export_import_and_save() {
+    for name in ["First\tName", "\tName", "Name\t", "Name\t\"quoted\"", "Name\nwith\ta tab"] {
+        let mut source = one_field();
+        add_field(&mut source, 0, [50.0, 650.0, 250.0, 670.0], &NewField::Text { multiline: false }, Some("Other")).unwrap();
+        set_value(&mut source, "Other", &FieldValue::Text("other field".into())).unwrap();
+        let field = fields(&source).into_iter().find(|f| f.name == "Name").unwrap().obj;
+        source.update_dict(field, |dict| dict.set(b"T".to_vec(), PdfString::text(name))).unwrap();
+        set_value(&mut source, name, &FieldValue::Text("original, \"value\"".into())).unwrap();
+        let bytes = write_full(&source, &SaveOptions::default()).unwrap();
+        let source = Document::open(Arc::new(bytes.clone())).unwrap();
+        let row = data_values(&bytes).unwrap();
+        for csv in [export_data(&source, Format::Csv), merge_csv(&[row])] {
+            let mut doc = Document::open(Arc::new(bytes.clone())).unwrap();
+            set_value(&mut doc, name, &FieldValue::Text("replacement".into())).unwrap();
+            set_value(&mut doc, "Other", &FieldValue::Text("other replacement".into())).unwrap();
+            let report = import(&mut doc, csv.as_bytes()).unwrap();
+            assert_eq!(report.fields, 2);
+            assert!(report.rejected.is_empty(), "{:?}", report.rejected);
+            for saved in [write_full(&doc, &SaveOptions::default()).unwrap(), write_incremental(&doc, &SaveOptions::default()).unwrap()] {
+                let reopened = Document::open(Arc::new(saved)).unwrap();
+                assert_eq!(fields(&reopened).into_iter().find(|f| f.name == name).unwrap().value, vec!["original, \"value\""], "{csv:?}");
+                assert_eq!(values(&reopened), values(&source), "{csv:?}");
+            }
+        }
+    }
+}
+
+#[test]
+fn tabular_import_keeps_tsv_quotes_literal_and_csv_value_tabs() {
+    for name in ["Name", "Na\"me", "\"Name\"", "\"Name"] {
+        let mut doc = one_field();
+        add_field(&mut doc, 0, [50.0, 650.0, 250.0, 670.0], &NewField::Text { multiline: false }, Some("Other")).unwrap();
+        let field = fields(&doc).into_iter().find(|f| f.name == "Name").unwrap().obj;
+        doc.update_dict(field, |dict| dict.set(b"T".to_vec(), PdfString::text(name))).unwrap();
+        let text = format!("{name}\tOther\r\nAda\tother field\r\n");
+        let report = import(&mut doc, text.as_bytes()).unwrap();
+        assert_eq!(report.fields, 2, "{text:?}");
+        assert_eq!(fields(&doc).into_iter().find(|f| f.name == name).unwrap().value, vec!["Ada"]);
+    }
+    let mut doc = one_field();
+    add_field(&mut doc, 0, [50.0, 650.0, 250.0, 670.0], &NewField::Text { multiline: false }, Some("Other")).unwrap();
+    import(&mut doc, b"Name,Other\r\n\"Ada\tLovelace\",other field\r\n").unwrap();
+    assert_eq!(fields(&doc).into_iter().find(|f| f.name == "Name").unwrap().value, vec!["Ada\tLovelace"]);
+}

docs/roadmap.md

@@ -1,6 +1,6 @@
 # PdfCraft roadmap: milestones and what's next
 
-> **Last reviewed:** 2026-10-13 · **Last updated:** 2026-10-14 · **Change:** minor (M14: the Italian catalog has every entry the other catalogs had and the code looks up, 2,528 entries; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
+> **Last reviewed:** 2026-10-15 · **Last updated:** 2026-10-15 · **Change:** minor (M6: CSV tab-containing headers; estimates unchanged)
 > **Last reviewed:** 2026-10-12 · **Last updated:** 2026-10-13 · **Change:** minor (M2/M6: spot-colour images convert once per pixel value; widget placement and the Fields panel scale with the field count; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
 > **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-14 · **Change:** minor (M3 candidate: coordinate control clicks on slow frames and coalesced text selection; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
 > **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-14 · **Change:** minor (M3 #2080 candidate: explicit search jumps join per-tab history; rail and control-channel Back/Forward; estimates unchanged)
@@ -116,7 +116,7 @@ total matches the parity estimate.
 | M4 | Engine, history, save, organize | 100–180 | 95% | 8–15 | Done:<br>- command registry (menus, shortcuts and palette all use it);<br>- undo/redo; incremental, atomic and encrypted saves;<br>- autosave and crash recovery;<br>- organize, combine, extract, split and insert-from-file, with identical fonts and images stored once;<br>- CLI `edit/combine/extract/split`.<br>Done since: Combine files in its own tab (sortable, resizable columns; folders; early warnings; unlocking protected files), bookmark editing, page labels (Number pages), CLI `run`, Set Page Boxes, Crop tool, Duplicate pages, Ctrl+A / Cmd+A to select all pages in Organize, Replace pages, bookmarks from tagged headings. Missing: page transitions, recovery on the web M4: Insert-from-file preserves source bookmarks; integration tests retained with current main. |
 | M5 | Comments (all annotation types, XFDF) | 120–200 | 88% | 12–25 | Done: notes, highlight/underline/strikeout/squiggly, text boxes, ink, lines, arrows, rectangles, ovals, stamps (dynamic, Sign Here, Standard Business), with appearance streams; replies, status, checkmarks, locking, move/resize/restyle/delete; properties dialog; panel filter and sort; hide all; summaries (comments only); XFDF/FDF import and export (partial imports preserve existing reply and review-status links); flatten; Fill & Sign with adjustable text/date size; agent tools.<br>Done since: stamps placed on a rotated page read upright (#1398); polygons, connected lines, clouds, callouts, inserted text, colour and checkmark filters; image signature pointer previews, selection handles and live image movement/resizing with proportional corners and independent edge handles. Missing: custom stamps, replace-text proposals, summary layouts with the page |
 | M5 | Comments (all annotation types, XFDF) | 120–200 | 88% | 12–25 | Done: notes, highlight/underline/strikeout/squiggly, text boxes, ink, lines, arrows, rectangles, ovals, stamps (dynamic, Sign Here, Standard Business), with appearance streams; replies, status, checkmarks, locking, move/resize/restyle/delete; properties dialog; panel filter and sort; hide all; summaries (comments only); XFDF/FDF import and export (partial imports preserve existing reply and review-status links); flatten; Fill & Sign with adjustable text/date size; agent tools.<br>Done since: polygons, connected lines, clouds, callouts, inserted text, colour and checkmark filters; image signature pointer previews, selection handles and live image movement/resizing with proportional corners and independent edge handles. A refused restyle or resize of a text box another program drew leaves that comment unchanged (#1327). Make Current Properties Default on an arrow updates arrows, not plain lines (#1302). Flattening keeps a visible comment it cannot draw (#1317). Missing: custom stamps, replace-text proposals, summary layouts with the page |
-| M6 | Forms + JavaScript | 160–320 | 50% | 40–75 | Done: filling all field types with regenerated appearances; Prepare a form (every field type, multi-select/shared properties, move/resize/delete, Field Properties General/Appearance/Position/Options/Format/Validate/Calculate); Acrobat's AF format/keystroke/validate/calculate functions and simplified field notation run natively in Acrobat's event order; tab order; push-button actions; flatten; agent tools. Form data exchange (FDF, XFDF, XML, CSV, text) done; XFDF values retain text across XML comments and processing instructions.<br>Done since: JavaScript engine (boa, sandboxed) running custom keystroke/validate/calculate/format and button scripts, document JavaScripts, console. Missing: Actions tab, wider object model (annotations, layers, dialogs), XFA<br>Done since: Multi-select choice fields write ascending `/I` option indices while preserving `/V` selection order; synthetic forms/engine regressions cover reverse selection and save/reopen. CSV export preserves carriage returns in names and values. |
+| M6 | Forms + JavaScript | 160–320 | 50% | 40–75 | Done: filling all field types with regenerated appearances; Prepare a form (every field type, multi-select/shared properties, move/resize/delete, Field Properties General/Appearance/Position/Options/Format/Validate/Calculate); Acrobat's AF format/keystroke/validate/calculate functions and simplified field notation run natively in Acrobat's event order; tab order; push-button actions; flatten; agent tools. Form data exchange (FDF, XFDF, XML, CSV, text) done; XFDF values retain text across XML comments and processing instructions. CSV export and spreadsheet merging quote tabs, and import distinguishes quoted tabs from TSV delimiters without changing field identities.<br>Done since: JavaScript engine (boa, sandboxed) running custom keystroke/validate/calculate/format and button scripts, document JavaScripts, console. Missing: Actions tab, wider object model (annotations, layers, dialogs), XFA<br>Done since: Multi-select choice fields write ascending `/I` option indices while preserving `/V` selection order; synthetic forms/engine regressions cover reverse selection and save/reopen. CSV export preserves carriage returns in names and values. |
 | M7 | Content editing (text, images, header/footer, watermark) | 250–500 | 20% | 100–180 | Done: header & footer, watermarks, backgrounds, Bates; added text and images that stay editable (move, resize, format, rotate, flip, crop, replace); links (Link tool, Link Properties, create from URLs, remove all). Done since: Edit text preserves Arabic/Hebrew `/ActualText` typing order, with font-independent regressions; single-glyph RTL ligature spans (including lam-alef) join their surrounding word. Done since (#1116): editable text regions grouped across compatible words and subset fonts, one rich-text editor over a background with the source text removed, embedded sfnt faces reused as editor faces, and visible (clipped) bounds for cropped-image selection and resize. Exclusive crops now resize across nested states and content streams, with shared clips fixed.<br>Done since: #594 ordinary paragraph drags preserve overlapping source text; UI/engine regressions, native save/reopen, independent-reader checks and full CI passed in the Linux test environment. #1200 candidate: local GoToR links open in desktop tabs and through root-confined automation; appearance-only edits preserve existing actions. Named destinations remain unapplied and `/NewWindow` is a tab hint. Missing: editing existing text and images in place (the longest pole), image/PDF watermarks |
 | M7 | Content editing (text, images, header/footer, watermark) | 250–500 | 20% | 100–180 | Done: header & footer, watermarks, backgrounds, Bates; added text and images that stay editable (move, resize, format, rotate, flip, crop, replace); links (Link tool, Link Properties, create from URLs, remove all). Done since: Edit text preserves Arabic/Hebrew `/ActualText` typing order, with font-independent regressions. Done since (#1116): editable text regions grouped across compatible words and subset fonts, one rich-text editor over a background with the source text removed, embedded sfnt faces reused as editor faces, and visible (clipped) bounds for cropped-image selection and resize. Exclusive crops now resize across nested states and content streams, with shared clips fixed.<br>Done since: #594 ordinary paragraph drags preserve overlapping source text; UI/engine regressions, native save/reopen, independent-reader checks and full CI passed in the Linux test environment. #1200 candidate: local GoToR links open in desktop tabs and through root-confined automation; appearance-only edits preserve existing actions. Named destinations remain unapplied and `/NewWindow` is a tab hint. #1316: replacing a line or paragraph keeps a neighbouring line whose glyph box overlaps when the baselines differ; a second copy on the same baseline is still replaced. Missing: editing existing text and images in place (the longest pole), image/PDF watermarks |
 | M7 | Content editing (text, images, header/footer, watermark) | 250–500 | 20% | 100–180 | Done: header & footer, watermarks, backgrounds, Bates; added text and images that stay editable (move, resize, format, rotate, flip, crop, replace); links (Link tool, Link Properties, create from URLs, remove all). Missing: editing existing text and images in place (the longest pole), watermark print/screen visibility and repeat |
@@ -179,6 +179,7 @@ M2 (renderer), M7 (content editing), M10 (OCR and Office), M11 (Preflight and st
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-15 | minor | M6: CSV export and spreadsheet merging quote tabs, and import distinguishes quoted tabs from TSV delimiters without changing field identities. Estimates unchanged. |
 | 2026-10-12 | minor | M6: valid AcroForm XML element names with original PDF field names preserved; saved-PDF collision and Unicode regressions. Estimates unchanged. |
 | 2026-10-12 | minor | M6: preserve carriage returns in exported CSV field names and values; saved-PDF round-trip coverage. Estimates unchanged. |
 | 2026-10-12 | minor | M7 local candidate: text drafts grow and save their width; single visual rows grow across style boundaries; both text tools retype added items and Add Text edits source text. Added-item textless previews are read-only and covered by UI/tool regressions. Estimates unchanged. |

parity/acrobat-features.toml

@@ -4704,8 +4704,8 @@ milestone = "M6"
 status = "shipped"
 commands = ["form.export_data", "form.import_data"]
 tools = ["doc_export_data", "doc_import_data"]
-evidence = ["crates/xfdf/src/tests.rs::form_data_as_xml_csv_and_text", "crates/automation/tests/automation.rs::comments_and_form_data_travel_as_xfdf_fdf_and_text"]
-notes = "Acrobat's XML (xfdf:original), CSV, tab-delimited"
+evidence = ["crates/xfdf/src/tests.rs::form_data_as_xml_csv_and_text", "crates/automation/tests/automation.rs::comments_and_form_data_travel_as_xfdf_fdf_and_text", "crates/xfdf/src/tests.rs::csv_headers_with_tabs_survive_export_import_and_save", "crates/xfdf/src/tests.rs::tabular_import_keeps_tsv_quotes_literal_and_csv_value_tabs"]
+notes = "Acrobat's XML (xfdf:original), CSV, tab-delimited; CSV export and spreadsheet merging quote tabs, and import distinguishes quoted tabs from TSV delimiters without changing field identities. Ambiguous externally authored tables remain heuristic; TSV export and formula-cell policy are unchanged."
 
 [[feature]]
 id = "form.merge-to-spreadsheet"
@@ -4716,8 +4716,8 @@ milestone = "M6"
 status = "shipped"
 commands = ["form.merge_data"]
 tools = ["form_merge_data"]
-evidence = ["crates/xfdf/src/tests.rs::data_files_merge_into_a_spreadsheet", "crates/automation/tests/automation.rs::merging_form_data_into_a_spreadsheet", "crates/ui-egui/tests/javascript.rs::merge_data_files_into_a_spreadsheet"]
-notes = "FDF, XFDF or filled-in PDF forms \u2192 CSV, a column per field and a row per file."
+evidence = ["crates/xfdf/src/tests.rs::data_files_merge_into_a_spreadsheet", "crates/automation/tests/automation.rs::merging_form_data_into_a_spreadsheet", "crates/ui-egui/tests/javascript.rs::merge_data_files_into_a_spreadsheet", "crates/xfdf/src/tests.rs::csv_headers_with_tabs_survive_export_import_and_save"]
+notes = "FDF, XFDF or filled-in PDF forms \u2192 CSV, a column per field and a row per file. CSV header tabs, quotes and line breaks retain field identities through import and save/reopen; ambiguous external table detection remains heuristic."
 
 [[feature]]
 id = "form.flatten-fields"