Merge PR #1600: XLSX: keep header and footer pictures on save

Conflicts:
- docs/file-format-parity.md: kept main's header and log rows, added this PR's change phrase and row once

crates/xlsx/src/passthrough.rs

@@ -6,7 +6,8 @@
 //! their `<externalReferences>`, data connections, XML maps) and each sheet (query tables, cells
 //! mapped to XML elements, form controls, ActiveX controls, OLE objects, the sheet background and
 //! printer settings, with the sheet's `<picture>`, `<oleObjects>` and `<controls>` XML, the `r:id`
-//! of `<pageSetup>` and the legacy VML shapes those controls need). The workbook also keeps its
+//! of `<pageSetup>`, the legacy VML shapes those controls need and the pictures of the headers and
+//! footers, `&G`, with their `<legacyDrawingHF>`). The workbook also keeps its
 //! `<fileVersion>` and the calcFeatures extension, which Excel needs to trust the saved values.
 //!
 //! On write, kept parts get fresh part names where needed and new relationship ids; the `r:id`s in
@@ -92,7 +93,7 @@ const FILE_VERSION_ATTRS: &[&str] = &["appName", "lastEdited", "lowestEdited", "
 const CALC_FEATURES_URI: &str = "{B58B0392-4F1F-4190-BB64-5DF3571DCE5F}";
 const NS_CALC_FEATURES: &str = "http://schemas.microsoft.com/office/spreadsheetml/2018/calcfeatures";
 /// Kept sheet elements, in schema order (all after `<legacyDrawing>`, before `<tableParts>`).
-const SHEET_SLOTS: &[&str] = &["picture", "oleObjects", "controls"];
+const SHEET_SLOTS: &[&str] = &["legacyDrawingHF", "picture", "oleObjects", "controls"];
 
 /// Relationship kinds GridCraft reads and rewrites, or that depend on content it rewrites:
 /// kept content whose graph reaches one of them is dropped.
@@ -479,7 +480,10 @@ impl KeptReader {
                 cx.warn(format!("sheet \"{name}\": {} was dropped: {why}", kind(&r.rel_type)));
             }
         }
-        if rels.iter().any(|r| is_kind(r, SHEET_ELEMENT_KINDS)) {
+        // Notes have one VML drawing per sheet; another one holds the header and footer pictures.
+        let vml_drawings = rels.iter().filter(|r| is_kind(r, &["vmlDrawing"])).count();
+        let notes = rels.iter().filter(|r| is_kind(r, &["comments"])).count();
+        if rels.iter().any(|r| is_kind(r, SHEET_ELEMENT_KINDS)) || vml_drawings > notes {
             self.sheet_elements(cx, part, name, &rels, &mut p, &mut seen);
         }
         (!p.is_empty()).then(|| Arc::new(p))
@@ -503,6 +507,21 @@ impl KeptReader {
                 Err(why) => cx.warn(format!("sheet \"{name}\": printer settings were dropped: {why}")),
             }
         }
+        // Header and footer pictures (`&G`): a VML drawing of their own and the images it shows,
+        // kept byte for byte (GridCraft writes the header text, not the pictures).
+        if let Some(id) = scan.legacy_drawing_hf.as_deref()
+            && scan.legacy_drawing.as_deref() != Some(id)
+            && let Some(r) = rels.iter().find(|r| r.id == id && is_kind(r, &["vmlDrawing"]))
+        {
+            match self.keep_through(cx, p, std::slice::from_ref(r), seen, &["vmlDrawing"]) {
+                Ok(()) => {
+                    let xml = format!("<legacyDrawingHF xmlns:r=\"{NS_REL}\" r:id=\"{}\"/>", esc_attr(&r.id));
+                    p.elements.push(PreservedXml { slot: "legacyDrawingHF".into(), xml });
+                    cx.warn(format!("sheet \"{name}\": pictures in the header and footer are not shown; they are kept for saving"));
+                }
+                Err(why) => cx.warn(format!("sheet \"{name}\": header and footer pictures were dropped: {why}")),
+            }
+        }
         let mut frags = scan.fragments;
         // Controls and OLE objects are drawn from shapes in the legacy VML drawing.
         if frags.iter().any(|(slot, _)| slot != "picture") {
@@ -581,18 +600,20 @@ struct SheetScan {
     /// (slot, XML with the namespace declarations it needs).
     fragments: Vec<(String, String)>,
     legacy_drawing: Option<String>,
+    /// The relationship id on `<legacyDrawingHF>` (header and footer pictures).
+    legacy_drawing_hf: Option<String>,
     /// The relationship id on `<pageSetup>` (printer settings).
     page_setup: Option<String>,
 }
 
 /// Finds the sheet's `<picture>`, `<oleObjects>`, `<controls>` (also inside
-/// `<mc:AlternateContent>`) and the `<legacyDrawing>` id. `None` when the XML is damaged.
+/// `<mc:AlternateContent>`) and the `<legacyDrawing>` and `<legacyDrawingHF>` ids. `None` when the XML is damaged.
 fn scan_sheet(bytes: &[u8]) -> Option<SheetScan> {
     let data = xml::to_utf8(bytes);
     let text = std::str::from_utf8(&data).ok()?;
     let mut reader = Reader::from_str(text);
     let mut decls: Vec<(String, String)> = vec![];
-    let mut out = SheetScan { fragments: vec![], legacy_drawing: None, page_setup: None };
+    let mut out = SheetScan { fragments: vec![], legacy_drawing: None, legacy_drawing_hf: None, page_setup: None };
     let mut in_root = false;
     loop {
         let start = usize::try_from(reader.buffer_position()).ok()?;
@@ -614,6 +635,7 @@ fn scan_sheet(bytes: &[u8]) -> Option<SheetScan> {
                 match local.as_slice() {
                     b"pageSetup" => out.page_setup = rel_id_attr(&e),
                     b"legacyDrawing" => out.legacy_drawing = rel_id_attr(&e),
+                    b"legacyDrawingHF" => out.legacy_drawing_hf = rel_id_attr(&e),
                     _ => {}
                 }
                 reader.read_to_end(e.name()).ok()?;
@@ -626,12 +648,12 @@ fn scan_sheet(bytes: &[u8]) -> Option<SheetScan> {
             }
             Event::Empty(e) if in_root => {
                 let local = e.local_name().as_ref().to_vec();
-                if local == b"legacyDrawing" || local == b"pageSetup" {
+                if local == b"legacyDrawing" || local == b"legacyDrawingHF" || local == b"pageSetup" {
                     let id = rel_id_attr(&e);
-                    if local == b"pageSetup" {
-                        out.page_setup = id;
-                    } else {
-                        out.legacy_drawing = id;
+                    match local.as_slice() {
+                        b"pageSetup" => out.page_setup = id,
+                        b"legacyDrawing" => out.legacy_drawing = id,
+                        _ => out.legacy_drawing_hf = id,
                     }
                 } else if local == b"picture"
                     && let Some(frag) = text.get(start..usize::try_from(reader.buffer_position()).ok()?)
@@ -738,6 +760,19 @@ fn shape_numbers(vml: &str) -> Vec<u64> {
         .collect()
 }
 
+/// The highest shape block VML text claims in `<o:idmap data>` or uses in a shape id.
+fn vml_block_max(vml: &str) -> u64 {
+    let used = shape_numbers(vml).into_iter().max().unwrap_or(0) / 1024;
+    let claimed = vml
+        .find("<o:idmap")
+        .and_then(|i| vml.get(i..)?.find("data=\"").map(|d| i + d + "data=\"".len()))
+        .and_then(|d| Some((d, d + vml.get(d..)?.find('"')?)))
+        .and_then(|(d, e)| vml.get(d..e))
+        .map(|list| list.split(',').filter_map(|b| b.trim().parse::<u64>().ok()).max().unwrap_or(0))
+        .unwrap_or(0);
+    used.max(claimed)
+}
+
 /// Kept VML (controls, OLE objects) plus GridCraft's note shapes: the notes get ids in a fresh
 /// shape block so they can't collide with the kept shapes the sheet XML refers to.
 fn merge_vml(kept: &str, ours: &str) -> String {
@@ -837,11 +872,27 @@ fn map_start(e: &BytesStart<'_>, prefixes: &mut HashSet<Vec<u8>>, map: &mut dyn
 pub struct KeptOut {
     used: HashSet<String>,
     n: u32,
+    /// The highest VML shape block a kept header and footer drawing uses: notes go after it.
+    vml_blocks: u32,
     /// Package-root relationships (type, target, external), added when `_rels/.rels` is written.
     root: Vec<(String, String, bool)>,
 }
 
 impl KeptOut {
+    /// Reserves the VML shape blocks the kept header and footer drawings of `wb` use, so that the
+    /// notes drawings GridCraft writes don't reuse their shape ids.
+    pub fn reserve_vml_blocks(&mut self, wb: &Workbook) {
+        let vmls =
+            wb.sheets.iter().filter_map(|s| s.preserved.as_deref()).flat_map(|p| &p.parts).filter(|q| q.content_type.eq_ignore_ascii_case(CT_VML));
+        let max = vmls.map(|q| vml_block_max(&String::from_utf8_lossy(&q.data))).max().unwrap_or(0);
+        self.vml_blocks = u32::try_from(max).unwrap_or(u32::MAX);
+    }
+
+    /// The shape block of the `n`th notes drawing.
+    pub fn notes_block(&self, n: u32) -> u32 {
+        n.saturating_add(self.vml_blocks)
+    }
+
     /// A part name for a kept part: its original name when that can't collide with anything
     /// written, otherwise a fresh one in the same folder.
     fn claim(&mut self, original: &str) -> String {

crates/xlsx/src/sheet_write.rs

@@ -551,7 +551,7 @@ pub fn write_sheet(wb: &Workbook, si: usize, selected: bool, out: &mut Out) -> (
         }
         out.default_type("vml", "application/vnd.openxmlformats-officedocument.vmlDrawing");
         let vml_name = format!("xl/drawings/vmlDrawing{n}.vml");
-        let vml = kept.notes_vml(vml_xml(sheet, n), &vml_name, out);
+        let vml = kept.notes_vml(vml_xml(sheet, out.kept.notes_block(n)), &vml_name, out);
         out.part(&vml_name, None, vml.into_bytes());
         rels.add("comments", &format!("../comments{n}.xml"));
         let rid = rels.add("vmlDrawing", &format!("../drawings/vmlDrawing{n}.vml"));

crates/xlsx/src/tests/passthrough_tests.rs

@@ -823,3 +823,97 @@ fn file_version_and_calc_features_survive_a_save() {
     let plain = Unpacked::new(&write_xlsx(&gridcraft_model::Workbook::new()).unwrap()).text("xl/workbook.xml");
     assert!(!plain.contains("fileVersion") && !plain.contains("extLst"), "{plain}");
 }
+
+const LOGO: &[u8] = b"\x89PNG\r\n\x1a\n letterhead logo";
+const SIGNATURE: &[u8] = b"\x89PNG\r\n\x1a\n footer signature";
+const HF_VML: &str = r##"<xml xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel"><o:shapelayout v:ext="edit"><o:idmap v:ext="edit" data="1"/></o:shapelayout><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"/><v:shape id="LH" o:spid="_x0000_s1025" type="#_x0000_t75" style="position:absolute;margin-left:0;margin-top:0;width:120pt;height:40pt;z-index:1"><v:imagedata o:relid="rId1" o:title="logo"/><o:lock v:ext="edit" rotation="t"/></v:shape><v:shape id="CF" o:spid="_x0000_s1026" type="#_x0000_t75" style="position:absolute;margin-left:0;margin-top:0;width:80pt;height:20pt;z-index:2"><v:imagedata o:relid="rId2" o:title="signature"/><o:lock v:ext="edit" rotation="t"/></v:shape></xml>"##;
+
+/// #1257: a letterhead in the header and a picture in the footer (`&G`), drawn from a VML part
+/// that `<legacyDrawingHF>` names, next to a note whose VML drawing GridCraft rewrites.
+fn header_picture_package() -> Vec<u8> {
+    let types = r#"<?xml version="1.0"?><Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types"><Default Extension="xml" ContentType="application/xml"/><Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/><Default Extension="png" ContentType="image/png"/><Default Extension="vml" ContentType="application/vnd.openxmlformats-officedocument.vmlDrawing"/><Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/><Override PartName="/xl/worksheets/sheet1.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/><Override PartName="/xl/comments1.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.comments+xml"/></Types>"#;
+    let workbook = format!(
+        r#"<?xml version="1.0"?><workbook xmlns="{NS_MAIN}" xmlns:r="{NS_R}"><sheets><sheet name="Invoice" sheetId="1" r:id="rId1"/></sheets></workbook>"#
+    );
+    let sheet = format!(
+        r#"<?xml version="1.0"?><worksheet xmlns="{NS_MAIN}" xmlns:r="{NS_R}"><sheetData><row r="1"><c r="A1"><v>1</v></c></row></sheetData><pageMargins left="0.7" right="0.7" top="0.75" bottom="0.75" header="0.3" footer="0.3"/><headerFooter><oddHeader>&amp;L&amp;G&amp;CInvoice</oddHeader><oddFooter>&amp;C&amp;G</oddFooter></headerFooter><legacyDrawing r:id="rId2"/><legacyDrawingHF r:id="rId3"/></worksheet>"#
+    );
+    let root_rels = rels(&[("rId1", "officeDocument", "xl/workbook.xml")]);
+    let wb_rels = rels(&[("rId1", "worksheet", "worksheets/sheet1.xml")]);
+    let sheet_rels = rels(&[
+        ("rId1", "comments", "../comments1.xml"),
+        ("rId2", "vmlDrawing", "../drawings/vmlDrawing1.vml"),
+        ("rId3", "vmlDrawing", "../drawings/vmlDrawing2.vml"),
+    ]);
+    let hf_rels = rels(&[("rId1", "image", "../media/image1.png"), ("rId2", "image", "../media/image2.png")]);
+    make_zip(&[
+        ("[Content_Types].xml", types.as_bytes()),
+        ("_rels/.rels", root_rels.as_bytes()),
+        ("xl/workbook.xml", workbook.as_bytes()),
+        ("xl/_rels/workbook.xml.rels", wb_rels.as_bytes()),
+        ("xl/worksheets/sheet1.xml", sheet.as_bytes()),
+        ("xl/worksheets/_rels/sheet1.xml.rels", sheet_rels.as_bytes()),
+        ("xl/comments1.xml", COMMENTS.as_bytes()),
+        ("xl/drawings/vmlDrawing1.vml", VML.as_bytes()),
+        ("xl/drawings/vmlDrawing2.vml", HF_VML.as_bytes()),
+        ("xl/drawings/_rels/vmlDrawing2.vml.rels", hf_rels.as_bytes()),
+        ("xl/media/image1.png", LOGO),
+        ("xl/media/image2.png", SIGNATURE),
+    ])
+}
+
+#[test]
+fn header_and_footer_pictures_survive_a_save() {
+    let (wb, rep) = read_xlsx(&header_picture_package()).unwrap();
+    assert!(!rep.warnings.iter().any(|w| w.contains("dropped")), "{:?}", rep.warnings);
+    assert_eq!(wb.sheet(0).unwrap().comments.len(), 1, "the note is modelled");
+    // Twice: what was kept on the first save is read back and kept again.
+    let (again, _) = read_xlsx(&write_xlsx(&wb).unwrap()).unwrap();
+    for saved in [write_xlsx(&wb).unwrap(), write_xlsx(&again).unwrap()] {
+        let u = Unpacked::new(&saved);
+        u.assert_valid();
+        let sheet = sheet_part(&u, "Invoice");
+        let sx = u.text(&sheet);
+        assert!(sx.contains("<oddHeader>&amp;L&amp;G&amp;CInvoice</oddHeader>"), "{sx}");
+        let (ty, vml) = u.target(&sheet, &attr_of(&sx, "legacyDrawingHF", "r:id"));
+        assert!(ty.ends_with("/vmlDrawing"), "{ty}");
+        assert_eq!(u.text(&vml), HF_VML);
+        let pictures: Vec<(String, Vec<u8>)> = u.rels(&vml).into_iter().map(|r| (r.0, u.parts.get(&r.2).unwrap().clone())).collect();
+        assert_eq!(pictures, [("rId1".to_string(), LOGO.to_vec()), ("rId2".to_string(), SIGNATURE.to_vec())]);
+        // The notes keep their own drawing; CT_Worksheet puts legacyDrawingHF right after it.
+        let notes = u.target(&sheet, &attr_of(&sx, "legacyDrawing", "r:id")).1;
+        assert_ne!(notes, vml);
+        assert!(u.text(&notes).contains("ObjectType=\"Note\""));
+        assert!(sx.find("<headerFooter").unwrap() < sx.find("<legacyDrawing ").unwrap());
+        assert!(sx.find("<legacyDrawing ").unwrap() < sx.find("<legacyDrawingHF ").unwrap());
+    }
+}
+
+/// The shape blocks a VML drawing claims (`<o:idmap data>`) and the blocks of its shape ids
+/// (`_x0000_s1025` is in block 1).
+fn vml_blocks(vml: &str) -> (Vec<u64>, Vec<u64>) {
+    let i = vml.find("<o:idmap").unwrap_or_else(|| panic!("no idmap in {vml}"));
+    let data = attr_of(&vml[i..], "o:idmap", "data");
+    let idmap = data.split(',').map(|b| b.trim().parse().unwrap()).collect();
+    let spids = vml
+        .match_indices("_x0000_s")
+        .map(|(j, m)| vml[j + m.len()..].chars().take_while(char::is_ascii_digit).collect::<String>().parse::<u64>().unwrap() / 1024)
+        .collect();
+    (idmap, spids)
+}
+
+#[test]
+fn notes_take_shape_blocks_the_header_pictures_dont_use() {
+    let (wb, _) = read_xlsx(&header_picture_package()).unwrap();
+    let u = Unpacked::new(&write_xlsx(&wb).unwrap());
+    let sheet = sheet_part(&u, "Invoice");
+    let sx = u.text(&sheet);
+    let (hf_map, hf_ids) = vml_blocks(&u.text(&u.target(&sheet, &attr_of(&sx, "legacyDrawingHF", "r:id")).1));
+    let (notes_map, notes_ids) = vml_blocks(&u.text(&u.target(&sheet, &attr_of(&sx, "legacyDrawing", "r:id")).1));
+    assert_eq!((hf_map.as_slice(), hf_ids.as_slice()), ([1].as_slice(), [1, 1].as_slice()), "the header drawing is kept as it was");
+    assert!(!notes_ids.is_empty());
+    for b in notes_map.iter().chain(&notes_ids) {
+        assert!(!hf_map.contains(b) && !hf_ids.contains(b), "notes reuse shape block {b}: {notes_map:?} {notes_ids:?}");
+    }
+    assert!(notes_ids.iter().all(|b| notes_map.contains(b)), "note ids outside their drawing's blocks");
+}

crates/xlsx/src/write.rs

@@ -212,6 +212,7 @@ pub fn write_xlsx(wb: &Workbook, kind: XlsxKind) -> Result<Vec<u8>, IoError> {
         cell_pictures: Default::default(),
         kept: Default::default(),
     };
+    out.kept.reserve_vml_blocks(wb);
     out.default_type("rels", "application/vnd.openxmlformats-package.relationships+xml");
     out.default_type("xml", "application/xml");
 

docs/file-format-parity.md

@@ -1,6 +1,6 @@
 # File-format parity
 
-> **Last reviewed:** 2026-10-11 · **Last updated:** 2026-10-19 · **Change:** minor (legacy XLSX `INDEX`/`MATCH` formulas stay scalar on save; XLSX text keeps carriage returns on save and reopen; .xls dialog sheets are skipped instead of read as worksheets; `.xls` import reads each sheet's display options from WINDOW2: right-to-left, gridlines, headings, zeros, formulas; XLSX text boxes and shapes keep their paragraphs' right-to-left direction on save; CSV/TSV/TXT can open with every field kept as text via `file.open {csvAsText}`; formulas over Excel's 8,192 characters, and `%` or call chains past the nesting limit, are parse errors instead of stack overflows when a file is opened; XLSX PivotTables read and write `rowGrandTotals`/`colGrandTotals` the way Excel does, so a table saved with only one grand total opens with the right one; HTML export keeps right-to-left) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4
+> **Last reviewed:** 2026-10-11 · **Last updated:** 2026-10-19 · **Change:** minor (pictures in XLSX headers and footers are kept on save; legacy XLSX `INDEX`/`MATCH` formulas stay scalar on save; XLSX text keeps carriage returns on save and reopen; .xls dialog sheets are skipped instead of read as worksheets; `.xls` import reads each sheet's display options from WINDOW2: right-to-left, gridlines, headings, zeros, formulas; XLSX text boxes and shapes keep their paragraphs' right-to-left direction on save; CSV/TSV/TXT can open with every field kept as text via `file.open {csvAsText}`; formulas over Excel's 8,192 characters, and `%` or call chains past the nesting limit, are parse errors instead of stack overflows when a file is opened; XLSX PivotTables read and write `rowGrandTotals`/`colGrandTotals` the way Excel does, so a table saved with only one grand total opens with the right one; HTML export keeps right-to-left) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4
 
 Every format Excel opens or saves, with GridCraft's read and write support, fidelity and tests.
 Part of [target-app-parity.md](target-app-parity.md). **File formats: ~50% ready, 80–120 h**
@@ -25,7 +25,7 @@ and repair-free opening remain unverified.
 
 | Format | Excel | GridCraft read | GridCraft write | Fidelity / notes | Tests |
 |---|---|---|---|---|---|
-| `.xlsx` Excel Workbook (transitional) | R/W, native | yes | yes | Cells, shared/array/dynamic formulas, styles, themes, merges, CF, validation, tables, comments and notes, hyperlinks, names, freeze panes, outline, print settings, pictures, shapes, charts (simplified, see [chart-parity.md](chart-parity.md)), sparklines, PivotTables (caches and tables), protection, calc settings. **Kept unchanged on save (pass-through, `passthrough.rs`):** custom document properties, ribbon customisation and add-in task panes, custom XML, links to external workbooks (never followed or refreshed), data connections, sheet query tables, printer settings (#324), form controls, ActiveX controls, OLE objects and sheet backgrounds (with their VML shapes), and chart sheets (#727: the sheet, drawing, chart, style and colour parts are written back unchanged in their place, and left out when a sheet they plot was deleted or renamed or a worksheet took their name; they can't be edited or created); dropped when their sheet is deleted or their parts point at content GridCraft rewrites. **Not preserved:** slicers and slicer caches, timelines, data model, query tables attached to tables, sheet and workbook `extLst` entries we don't model, chart details; Strict Open XML files keep nothing. Never checked in Excel across a corpus: repair prompts unknown. 100 MB files fail (#175) | `roundtrip.rs`, `fixtures.rs`, `malformed.rs`, `pivot_tests.rs` |
+| `.xlsx` Excel Workbook (transitional) | R/W, native | yes | yes | Cells, shared/array/dynamic formulas, styles, themes, merges, CF, validation, tables, comments and notes, hyperlinks, names, freeze panes, outline, print settings, pictures, shapes, charts (simplified, see [chart-parity.md](chart-parity.md)), sparklines, PivotTables (caches and tables), protection, calc settings. **Kept unchanged on save (pass-through, `passthrough.rs`):** custom document properties, ribbon customisation and add-in task panes, custom XML, links to external workbooks (never followed or refreshed), data connections, sheet query tables, printer settings (#324), form controls, ActiveX controls, OLE objects and sheet backgrounds (with their VML shapes), pictures in headers and footers (`&G`, #1257: their VML drawing and images are written back unchanged; they are not shown, and can't be inserted), and chart sheets (#727: the sheet, drawing, chart, style and colour parts are written back unchanged in their place, and left out when a sheet they plot was deleted or renamed or a worksheet took their name; they can't be edited or created); dropped when their sheet is deleted or their parts point at content GridCraft rewrites. **Not preserved:** slicers and slicer caches, timelines, data model, query tables attached to tables, sheet and workbook `extLst` entries we don't model, chart details; Strict Open XML files keep nothing. Never checked in Excel across a corpus: repair prompts unknown. 100 MB files fail (#175) | `roundtrip.rs`, `fixtures.rs`, `malformed.rs`, `pivot_tests.rs` |
 | `.xlsx` Excel Workbook (transitional) | R/W, native | yes | yes | Cells, shared/array/dynamic formulas, styles, themes, merges, CF, validation, tables, notes (with their shown/hidden state) and threaded comments with replies, resolved state and timestamps (`threadedComments` and `persons` parts, #300), hyperlinks, names, freeze panes, outline, print settings, pictures, shapes, charts (simplified, see [chart-parity.md](chart-parity.md)), sparklines, PivotTables (caches and tables), protection, calc settings. **Not preserved:** unmodelled parts and extensions (form controls, slicer caches, timelines, external links, OLE objects, custom XML, data model, query tables, chart details). Never checked in Excel across a corpus: repair prompts unknown. 100 MB files fail (#175) | `roundtrip.rs`, `fixtures.rs`, `malformed.rs`, `pivot_tests.rs` |
 | `.xlsx` Excel Workbook (transitional) | R/W, native | yes | yes | Cells, shared/array/dynamic formulas, styles, themes, merges, CF, validation, tables, comments and notes, hyperlinks, names, freeze panes, outline, print settings, pictures, shapes, charts (simplified, see [chart-parity.md](chart-parity.md)), sparklines, PivotTables (caches and tables), protection, Allow Edit Ranges (`protectedRanges` with their password hashes, #307), calc settings. **Not preserved:** unmodelled parts and extensions (form controls, slicer caches, timelines, external links, OLE objects, custom XML, data model, query tables, chart details). Never checked in Excel across a corpus: repair prompts unknown. 100 MB files fail (#175) | `roundtrip.rs`, `fixtures.rs`, `malformed.rs`, `pivot_tests.rs` |
 | `.xlsx` Strict Open XML | R/W | yes | no (writes transitional) | Excel also saves transitional by default | fixtures |
@@ -94,6 +94,7 @@ refresh. Counted under features (Get & Transform, ~10% ready), not here.
 | 2026-10-18 | trivial | `file.open {csvAsText: true}` keeps every CSV/TSV/TXT field as the text the file holds, so identifiers (GTINs, SKUs, ZIP codes) keep their digits and leading zeros (#1808; a preference and a CLI flag are separate work) |
 | 2026-10-18 | trivial | XLSX PivotTables: `rowGrandTotals` is the Grand Total row and `colGrandTotals` the Grand Total column. Both were read and written the other way round, which a GridCraft round trip hid, so an Excel file with only one grand total opened showing the other |
 | 2026-10-19 | minor | HTML (Save as Web Page and clipboard) marks right-to-left sheets and right-to-left cell text with `dir` |
+| 2026-10-16 | trivial | XLSX: pictures in headers and footers (`&G`, the VML drawing `<legacyDrawingHF>` names and its images) are kept on save; they are still not shown (#1257) |
 | 2026-10-14 | trivial | Formula parser: text longer than Excel's 8,192 characters, and postfix chains (`1%%%…`, `f(1)(1)…`) past the 256-level nesting limit, are parse errors (the cell keeps its formula text and cached value) instead of trees deep enough to overflow the stack when a hostile file is opened, saved or dropped |
 | 2026-10-15 | minor | XLSX text preserves CR and CRLF across save/reopen; shared strings use `_x000D_` and other XML text uses `&#13;` (#1488) |
 | 2026-10-15 | minor | XLSX save keeps legacy `INDEX`/`MATCH` formulas scalar instead of marking them as dynamic arrays (#1505) |