Merge main into #853

# Conflicts:
#	ROADMAP.md
#	docs/file-format-parity.md

crates/engine/src/cf.rs

@@ -184,7 +184,7 @@ impl CfCache {
                 },
                 CfRule::TimePeriod { period, style } => match v.as_f64() {
                     Some(n) => {
-                        let today = gridcraft_calc::now_serial().floor();
+                        let today = gridcraft_core::date::serial_in_system(wb.date_system, gridcraft_calc::now_serial()).floor();
                         let d = n.floor();
                         let wd = gridcraft_core::date::datetime_from_serial(wb.date_system, today).map(|x| x.weekday as f64).unwrap_or(0.0);
                         let week_start = today - wd;

crates/engine/src/cmd/data.rs

@@ -198,27 +198,29 @@ fn sort(s: &mut Session, p: &Json) -> Result<Json> {
     let header = bool_param(p, "header").unwrap_or_else(|| guess_header(&d.wb, sh, r));
     let by_cols = str_param(p, "orientation") == Some("columns");
     let case = bool_param(p, "matchCase").unwrap_or(false);
-    let keys: Vec<SortKey> = p
-        .get("keys")
-        .and_then(Json::as_array)
-        .map(|a| {
-            a.iter()
-                .filter_map(|k| {
-                    let col = if by_cols {
-                        k.get("row").and_then(Json::as_u64).map(|r| r as u32 - 1).or_else(|| col_param(k.get("column"), r.start.row))?
-                    } else {
-                        col_param(k.get("column"), r.start.col)?
-                    };
-                    Some(SortKey {
-                        col,
-                        desc: k.get("order").and_then(Json::as_str) == Some("desc"),
-                        by: k.get("by").and_then(Json::as_str).unwrap_or("values").to_string(),
-                        list: k.get("customList").and_then(Json::as_array).map(|l| l.iter().filter_map(|x| x.as_str().map(str::to_string)).collect()),
-                    })
-                })
-                .collect()
-        })
-        .unwrap_or_default();
+    let mut keys: Vec<SortKey> = Vec::new();
+    for k in p.get("keys").and_then(Json::as_array).map(Vec::as_slice).unwrap_or_default() {
+        let col = if by_cols {
+            let row = match k.get("row").and_then(Json::as_u64) {
+                // Worksheet rows are 1-based; 0 (or a value past u32) has no coordinate.
+                Some(n) => {
+                    let row = u32::try_from(n).ok().and_then(|n| n.checked_sub(1));
+                    Some(row.ok_or_else(|| bad("data.sort", "sort key row must be 1 or greater"))?)
+                }
+                None => None,
+            };
+            row.or_else(|| col_param(k.get("column"), r.start.row))
+        } else {
+            col_param(k.get("column"), r.start.col)
+        };
+        let Some(col) = col else { continue };
+        keys.push(SortKey {
+            col,
+            desc: k.get("order").and_then(Json::as_str) == Some("desc"),
+            by: k.get("by").and_then(Json::as_str).unwrap_or("values").to_string(),
+            list: k.get("customList").and_then(Json::as_array).map(|l| l.iter().filter_map(|x| x.as_str().map(str::to_string)).collect()),
+        });
+    }
     if keys.is_empty() {
         s.ui_requests.push(crate::UiRequest::Dialog("sort".into(), json!({"range": r.a1(), "header": header})));
         return ok();
@@ -454,14 +456,24 @@ fn toggle_filter(s: &mut Session, p: &Json) -> Result<Json> {
     if has {
         return edit(s, |cx| {
             let sh = cx.sheet_mut(sheet)?;
+            // Reveal only rows the filter hid; rows hidden by hand or by a collapsed group stay hidden.
+            let filtered: Vec<u32> = sh.rows.keys().copied().filter(|r| sh.is_row_filtered(*r)).collect();
             sh.autofilter = None;
-            for info in sh.rows.values_mut() {
-                info.hidden = false;
+            for r in filtered {
+                if let Some(info) = sh.rows.get_mut(&r) {
+                    info.hidden = false;
+                }
             }
             cx.structural = true;
             Ok(json!({"filter": false}))
         });
     }
+    install_filter(s, p)
+}
+
+/// Turn a sheet AutoFilter on over `p.range`, or over the data range of the selection.
+fn install_filter(s: &mut Session, p: &Json) -> Result<Json> {
+    let sheet = s.doc()?.wb.active_sheet;
     let mut r = data_range(s, p)?;
     // A selected header row filters the data below it (#201).
     if p.get("range").is_none() && r.height() == 1 {
@@ -484,7 +496,7 @@ fn filter_by(s: &mut Session, p: &Json) -> Result<Json> {
     let af = match &sh.autofilter {
         Some(a) => a.clone(),
         None => {
-            toggle_filter(s, &json!({}))?;
+            install_filter(s, &json!({}))?;
             s.doc()?.wb.sheet(sheet).and_then(|sh| sh.autofilter.clone()).ok_or_else(|| EngineError::Other("no filter".into()))?
         }
     };
@@ -570,19 +582,28 @@ pub(crate) fn apply_filter(wb: &mut Workbook, sheet: usize) {
     let Some(af) = sh.autofilter.clone() else { return };
     let r = af.range;
     let mut hide = Vec::new();
-    // Precompute per-column numbers for top10/average.
-    let mut col_stats: std::collections::HashMap<u32, (Vec<f64>, f64)> = std::collections::HashMap::new();
-    for (off, c) in &af.criteria {
+    // Precompute per-criterion top10 threshold and average once, not per row.
+    let mut col_stats: std::collections::HashMap<usize, (Option<f64>, f64)> = std::collections::HashMap::new();
+    for (i, (off, c)) in af.criteria.iter().enumerate() {
         if matches!(c, FilterCriterion::Top10 { .. } | FilterCriterion::AboveAverage(_)) {
             let col = r.start.col + off;
-            let nums: Vec<f64> = (r.start.row + 1..=r.end.row).filter_map(|row| sh.value(CellRef::new(row, col)).as_f64()).collect();
+            let mut nums: Vec<f64> = (r.start.row + 1..=r.end.row).filter_map(|row| sh.value(CellRef::new(row, col)).as_f64()).collect();
             let avg = if nums.is_empty() { 0.0 } else { nums.iter().sum::<f64>() / nums.len() as f64 };
-            col_stats.insert(*off, (nums, avg));
+            let thr = match c {
+                FilterCriterion::Top10 { bottom, percent, count } => {
+                    nums.sort_by(|a, b| if *bottom { a.partial_cmp(b) } else { b.partial_cmp(a) }.unwrap_or(Ordering::Equal));
+                    let k = if *percent { ((nums.len() as f64) * (*count as f64) / 100.0).ceil() as usize } else { *count as usize };
+                    let k = k.clamp(1, nums.len().max(1));
+                    nums.get(k - 1).copied()
+                }
+                _ => None,
+            };
+            col_stats.insert(i, (thr, avg));
         }
     }
     for row in r.start.row + 1..=r.end.row {
         let mut visible = true;
-        for (off, crit) in &af.criteria {
+        for (i, (off, crit)) in af.criteria.iter().enumerate() {
             let c = CellRef::new(row, r.start.col + off);
             let v = sh.value(c);
             let text = crate::display::cell_text(wb, sh, c);
@@ -604,18 +625,14 @@ pub(crate) fn apply_filter(wb: &mut Workbook, sheet: usize) {
                         None => x,
                     }
                 }
-                FilterCriterion::Top10 { bottom, percent, count } => match (v.as_f64(), col_stats.get(off)) {
-                    (Some(n), Some((nums, _))) => {
-                        let mut sorted = nums.clone();
-                        sorted.sort_by(|a, b| if *bottom { a.partial_cmp(b) } else { b.partial_cmp(a) }.unwrap_or(Ordering::Equal));
-                        let k = if *percent { ((sorted.len() as f64) * (*count as f64) / 100.0).ceil() as usize } else { *count as usize };
-                        let k = k.clamp(1, sorted.len().max(1));
-                        let thr = sorted.get(k - 1).copied().unwrap_or(n);
+                FilterCriterion::Top10 { bottom, .. } => match (v.as_f64(), col_stats.get(&i)) {
+                    (Some(n), Some((thr, _))) => {
+                        let thr = thr.unwrap_or(n);
                         if *bottom { n <= thr } else { n >= thr }
                     }
                     _ => false,
                 },
-                FilterCriterion::AboveAverage(above) => match (v.as_f64(), col_stats.get(off)) {
+                FilterCriterion::AboveAverage(above) => match (v.as_f64(), col_stats.get(&i)) {
                     (Some(n), Some((_, avg))) => {
                         if *above {
                             n > *avg
@@ -896,7 +913,7 @@ fn subtract_range(r: RangeRef, cut: &RangeRef) -> Vec<RangeRef> {
 }
 
 /// Removes the cells of `cuts` from every validation, keeping the rest of each rule's ranges.
-fn remove_validation_cells(validations: &mut Vec<Validation>, cuts: &[RangeRef]) {
+pub(super) fn remove_validation_cells(validations: &mut Vec<Validation>, cuts: &[RangeRef]) {
     for dv in validations.iter_mut() {
         for cut in cuts {
             dv.ranges = dv.ranges.iter().flat_map(|r| subtract_range(*r, cut)).collect();
@@ -1046,6 +1063,18 @@ fn formula_at(f: &str, first: CellRef, at: CellRef) -> String {
     }
 }
 
+/// Moves the relative references of a rule formula written for `first` so it reads the same cells from `to`
+/// (pasting a rule); text without relative references (constants, literal lists) stays as typed.
+pub(super) fn move_rule_formula(f: &str, first: CellRef, to: CellRef) -> String {
+    if first == to {
+        return f.to_string();
+    }
+    let moved = formula_at(f, first, to);
+    let has_relative = gridcraft_formula::parse(f.trim_start_matches('=')).is_ok_and(|e| gridcraft_formula::print(&e) != moved);
+    let eq = if f.starts_with('=') { "=" } else { "" };
+    if has_relative { format!("{eq}{moved}") } else { f.to_string() }
+}
+
 fn compare_op(op: CfOperator, n: f64, a: Option<f64>, b: Option<f64>) -> bool {
     let Some(a) = a else { return false };
     match op {
@@ -1129,6 +1158,7 @@ fn group(s: &mut Session, p: &Json, on: bool) -> Result<Json> {
         {
             e.collapsed = false;
         }
+        cx.structural = true; // ungrouping reveals hidden rows: SUBTOTAL(10x) depends on it
         Ok(Json::Null)
     })
 }
@@ -1278,6 +1308,24 @@ fn subtotal(s: &mut Session, p: &Json) -> Result<Json> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn filter_by_inside_a_table_installs_the_autofilter_and_keeps_the_button() {
+        for sel in [json!({"cell": "A1"}), json!({"cell": "A2"}), json!({"range": "A1:A3"})] {
+            let mut s = Session::new();
+            s.new_workbook();
+            s.execute("range.setValues", json!({"range": "A1", "values": [["H"], ["a"], ["b"]]})).unwrap();
+            s.execute("insert.table", json!({"range": "A1:A3", "header": true})).unwrap();
+            s.execute("selection.set", sel.clone()).unwrap();
+            s.execute("data.filterBy", json!({"column": "A", "values": ["a"]})).unwrap();
+            let sh = s.doc().unwrap().wb.active().unwrap();
+            assert_eq!(sh.autofilter.as_ref().map(|a| a.range.a1()), Some("A1:A3".to_string()), "{sel}");
+            assert!(sh.tables[0].filter_button, "{sel}");
+            assert!(!sh.is_row_hidden(1), "{sel}");
+            assert!(sh.is_row_hidden(2), "{sel}");
+            assert_eq!(sh.value(CellRef::new(2, 0)).display(), "b", "{sel}");
+        }
+    }
+
     #[test]
     fn partial_validation_edits_keep_the_rest_of_the_old_rule() {
         let mut s = Session::new();
@@ -1300,6 +1348,45 @@ mod tests {
         assert!(!ok(&mut s, "B1", "150"));
     }
 
+    #[test]
+    fn removing_an_autofilter_keeps_manually_hidden_and_collapsed_rows() {
+        let mut s = Session::new();
+        s.new_workbook();
+        s.execute("range.setValues", json!({"range": "A1", "values": [["H"], ["a"], ["b"], ["c"]]})).unwrap();
+        s.execute("range.setValues", json!({"range": "A10", "values": [["z"]]})).unwrap();
+        s.execute("data.group", json!({"rows": "2:4"})).unwrap();
+        s.execute("data.hideDetail", json!({"rows": "2:4"})).unwrap();
+        s.execute("home.hideRows", json!({"rows": "10:10"})).unwrap();
+        let hidden = |s: &Session| -> Vec<u32> {
+            let sh = s.doc().unwrap().wb.active().unwrap();
+            sh.rows.iter().filter(|(_, l)| l.hidden).map(|(r, _)| *r).collect()
+        };
+        let before = hidden(&s);
+        assert_eq!(before, [1, 2, 3, 9]);
+        s.execute("data.filter", json!({"range": "A1:A4"})).unwrap();
+        s.execute("data.filter", json!({"range": "A1:A4"})).unwrap();
+        assert!(s.doc().unwrap().wb.active().unwrap().autofilter.is_none());
+        assert_eq!(hidden(&s), before);
+        assert_eq!(row_state(&s, 4..=4), [(false, true)]);
+    }
+
+    #[test]
+    fn table_dropdown_setup_outside_the_table_keeps_manually_hidden_rows() {
+        let mut s = Session::new();
+        s.new_workbook();
+        s.execute("range.setValues", json!({"range": "A1", "values": [["H"], ["a"], ["b"], ["c"]]})).unwrap();
+        s.execute("range.setValues", json!({"range": "A10", "values": [["z"]]})).unwrap();
+        s.execute("insert.table", json!({"range": "A1:A4", "header": true})).unwrap();
+        s.execute("home.hideRows", json!({"rows": "3:3"})).unwrap();
+        s.execute("home.hideRows", json!({"rows": "10:10"})).unwrap();
+        s.execute("selection.set", json!({"range": "E1"})).unwrap();
+        // The table filter dropdown installs an AutoFilter on demand by toggling `data.filter` twice.
+        s.execute("data.filter", json!({"range": "A1:A4"})).unwrap();
+        s.execute("data.filter", json!({"range": "A1:A4"})).unwrap();
+        let sh = s.doc().unwrap().wb.active().unwrap();
+        assert_eq!(sh.rows.iter().filter(|(_, l)| l.hidden).map(|(r, _)| *r).collect::<Vec<_>>(), [2, 9]);
+    }
+
     /// Rows 5:8 grouped, with 6:7 grouped again inside (0-based 4..=7 and 5..=6).
     fn nested_rows() -> Session {
         let mut s = Session::new();
@@ -1375,6 +1462,18 @@ mod tests {
         assert_eq!(sc("data.ungroup"), Some("Alt+Shift+Left"));
     }
 
+    #[test]
+    fn column_sort_rejects_row_key_zero_without_panicking() {
+        let mut s = Session::new();
+        s.new_workbook();
+        s.execute("cell.set", json!({"cell": "A1", "input": "2"})).unwrap();
+        for row in [0u64, 1 << 32] {
+            let params = json!({"range": "A1:B2", "header": false, "orientation": "columns", "keys": [{"row": row}]});
+            let err = s.execute("data.sort", params).unwrap_err();
+            assert!(matches!(err, EngineError::BadParams { .. }), "row {row}: {err:?}");
+        }
+    }
+
     #[test]
     fn split() {
         assert_eq!(split_delimited("a,b,,c", &[','], false, '"'), ["a", "b", "", "c"]);

crates/engine/src/cmd/edit.rs

@@ -219,11 +219,8 @@ fn cell_set(s: &mut Session, p: &Json) -> Result<Json> {
         Some(c) => c,
         None => s.doc()?.selection.active,
     };
-    let input = str_param(p, "input")
-        .or_else(|| str_param(p, "value"))
-        .map(str::to_string)
-        .or_else(|| p.get("value").map(json_to_input))
-        .ok_or_else(|| bad("cell.set", "missing `input` (or `value`)"))?;
+    // Both spellings take a string, number or boolean, as typed (#697).
+    let input = p.get("input").or_else(|| p.get("value")).map(json_to_input).ok_or_else(|| bad("cell.set", "missing `input` (or `value`)"))?;
     let array = bool_param(p, "array").unwrap_or(false);
     let d = s.doc()?;
     if let Some(sh) = d.wb.sheet(sheet)
@@ -420,14 +417,7 @@ fn selection_move(s: &mut Session, p: &Json) -> Result<Json> {
     let Some(sheet) = d.wb.active() else { return Err(EngineError::NoDocument) };
     let sel = &mut d.selection;
     // Extension moves the far corner, not the active cell.
-    let from = if extend {
-        let r = sel.current();
-        let far_row = if sel.anchor.row == r.start.row { r.end.row } else { r.start.row };
-        let far_col = if sel.anchor.col == r.start.col { r.end.col } else { r.start.col };
-        CellRef::new(far_row, far_col)
-    } else {
-        sel.active
-    };
+    let from = if extend { sel.moving_end() } else { sel.active };
     // Skip hidden rows/columns and step over merged areas.
     let mut to = if jmp {
         jump(sheet, from, dr.signum(), dc.signum())
@@ -1111,6 +1101,20 @@ fn paste_special(s: &mut Session, p: &Json) -> Result<Json> {
                                 }
                             }
                         }
+                        // The copied cell's validation rule replaces whatever rule the destination had.
+                        if !link && matches!(what, What::All | What::AllExceptBorders | What::Validation) {
+                            let rule = src_sheet.validations.iter().find(|dv| dv.ranges.iter().any(|r| r.contains(sc))).cloned();
+                            let sh = cx.sheet_mut(dest_sheet)?;
+                            super::data::remove_validation_cells(&mut sh.validations, &[RangeRef::new(dest, dest)]);
+                            if let Some(mut dv) = rule {
+                                // Relative references move with the rule, as pasted formulas do.
+                                let first = dv.ranges.first().map_or(sc, |r| r.start);
+                                dv.f1 = super::data::move_rule_formula(&dv.f1, first, dest);
+                                dv.f2 = dv.f2.map(|f| super::data::move_rule_formula(&f, first, dest));
+                                dv.ranges = vec![RangeRef::new(dest, dest)];
+                                sh.validations.push(dv);
+                            }
+                        }
                         match what {
                             What::Comments => {
                                 if let Some(cm) = src_sheet.comments.get(&sc).cloned() {
@@ -1583,6 +1587,23 @@ fn begin_edit(s: &mut Session, _: &Json) -> Result<Json> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn cell_set_takes_numbers_for_input_and_value() {
+        // #697: a JSON number for `input` used to clear the cell instead of entering it.
+        let mut s = Session::new();
+        s.new_workbook();
+        s.execute("cell.set", json!({"cell": "A1", "input": 123.5})).unwrap();
+        s.execute("cell.set", json!({"cell": "A2", "value": 77})).unwrap();
+        s.execute("cell.set", json!({"cell": "A3", "input": true})).unwrap();
+        s.execute("cell.set", json!({"cell": "A4", "input": "=A1+A2"})).unwrap();
+        let get = |s: &mut Session, a: &str| s.execute("cell.get", json!({"cell": a})).unwrap();
+        assert_eq!(get(&mut s, "A1")["value"], json!(123.5));
+        assert_eq!(get(&mut s, "A2")["value"], json!(77.0));
+        assert_eq!(get(&mut s, "A3")["value"], json!(true));
+        assert_eq!(get(&mut s, "A4")["value"], json!(200.5));
+        assert!(s.execute("cell.set", json!({"cell": "A5"})).is_err());
+    }
+
     #[test]
     fn legacy_array_entry() {
         let mut s = Session::new();

crates/engine/src/cmd/extra.rs

@@ -701,6 +701,12 @@ fn stash_get(wb: &Workbook, key: &str) -> Json {
         .unwrap_or(json!({}))
 }
 
+/// Like `stash_get`, for the name-keyed lists (views, scripts): a stored value that is not a JSON object is treated as empty.
+fn stash_map(wb: &Workbook, key: &str) -> Json {
+    let v = stash_get(wb, key);
+    if v.is_object() { v } else { json!({}) }
+}
+
 fn stash_set(wb: &mut Workbook, key: &str, v: &Json) {
     let text = v.to_string();
     let formula = format!("\"{}\"", text.replace('"', "\"\""));
@@ -723,7 +729,7 @@ pub(crate) fn keep_watch_list(from: &Workbook, to: &mut std::sync::Arc<Workbook>
 
 fn custom_views(s: &mut Session, p: &Json) -> Result<Json> {
     let d = s.doc()?;
-    let mut views = stash_get(&d.wb, VIEWS_NAME);
+    let mut views = stash_map(&d.wb, VIEWS_NAME);
     if let Some(name) = str_param(p, "save") {
         let sh = d.wb.active().ok_or(EngineError::NoDocument)?;
         views[name] = json!({"sheet": d.wb.active_sheet, "selection": d.selection.a1(), "zoom": sh.zoom, "freeze": sh.freeze});
@@ -743,6 +749,17 @@ fn custom_views(s: &mut Session, p: &Json) -> Result<Json> {
         if let Some(z) = v["zoom"].as_u64() {
             s.execute("view.zoom", json!({"percent": z}))?;
         }
+        if let Some(f) = v.get("freeze") {
+            let freeze = match (f[0].as_u64(), f[1].as_u64()) {
+                (Some(r), Some(c)) => u32::try_from(r).ok().zip(u32::try_from(c).ok()),
+                _ => None,
+            };
+            edit(s, |cx| {
+                let si = cx.sheet_index();
+                cx.sheet_mut(si)?.freeze = freeze;
+                Ok(())
+            })?;
+        }
     } else if let Some(name) = str_param(p, "delete") {
         if let Some(o) = views.as_object_mut() {
             o.remove(name);
@@ -812,7 +829,7 @@ fn table_resize(s: &mut Session, p: &Json) -> Result<Json> {
         let sheet = cx.sheet_mut(si)?;
         let headers: Vec<String> = (r.start.col..=r.end.col).map(|c| sheet.value(CellRef::new(r.start.row, c)).display()).collect();
         let t = sheet.tables.get_mut(ti).ok_or_else(|| bad("table", "gone"))?;
-        if r.start.row != t.range.start.row {
+        if r.start.row != t.range.start.row || !r.intersects(&t.range) {
             return Err(EngineError::Other(
                 "The headers must remain in the same row, and the resulting table range must overlap the original table range.".into(),
             ));
@@ -938,7 +955,7 @@ fn new_script(s: &mut Session, p: &Json) -> Result<Json> {
         return Err(bad("automate.newScript", "`commands` must be an array"));
     }
     edit(s, |cx| {
-        let mut all = stash_get(&cx.wb, SCRIPTS_NAME);
+        let mut all = stash_map(&cx.wb, SCRIPTS_NAME);
         all[name.as_str()] = cmds.clone();
         stash_set(&mut cx.wb, SCRIPTS_NAME, &all);
         Ok(json!({"name": name}))
@@ -977,7 +994,7 @@ fn run_script(s: &mut Session, p: &Json) -> Result<Json> {
 fn delete_script(s: &mut Session, p: &Json) -> Result<Json> {
     let name = str_param(p, "name").ok_or_else(|| bad("automate.deleteScript", "missing `name`"))?.to_string();
     edit(s, |cx| {
-        let mut all = stash_get(&cx.wb, SCRIPTS_NAME);
+        let mut all = stash_map(&cx.wb, SCRIPTS_NAME);
         if let Some(o) = all.as_object_mut() {
             o.remove(&name);
         }
@@ -1052,8 +1069,13 @@ fn toggle_checkbox(s: &mut Session, p: &Json) -> Result<Json> {
     })
 }
 
+/// Copy of the params that is always a JSON object, so keys can be assigned; any other JSON value counts as no params (like null).
+fn object_params(p: &Json) -> Json {
+    Json::Object(p.as_object().cloned().unwrap_or_default())
+}
+
 fn theme_colors(s: &mut Session, p: &Json) -> Result<Json> {
-    let mut params = p.clone();
+    let mut params = object_params(p);
     if params.get("name").is_none() {
         params["name"] = json!(s.doc()?.wb.theme.name.clone());
     }
@@ -1074,7 +1096,7 @@ fn background(s: &mut Session, p: &Json) -> Result<Json> {
             Ok(Json::Null)
         });
     }
-    let mut params = p.clone();
+    let mut params = object_params(p);
     params["alt"] = json!("Sheet background");
     params["at"] = json!("A1");
     s.execute("insert.picture", params)
@@ -1090,7 +1112,7 @@ fn draw_border(s: &mut Session, p: &Json) -> Result<Json> {
         "outline" => "outside",
         _ => "all",
     };
-    let mut params = p.clone();
+    let mut params = object_params(p);
     params["preset"] = json!(preset);
     s.execute("home.borders", params)
 }

crates/engine/src/cmd/file.rs

@@ -75,7 +75,11 @@ fn open(s: &mut Session, p: &Json) -> Result<Json> {
     {
         s.close_document(0);
     }
-    let i = s.add_document(DocState::new(wb, path, title));
+    let mut doc = DocState::new(wb, path, title);
+    if crate::io::FileKind::from_path(&name).is_none() && gridcraft_xlsx::sniff(&bytes) == gridcraft_xlsx::Format::Xlsx {
+        doc.content_kind = Some(crate::io::FileKind::Xlsx);
+    }
+    let i = s.add_document(doc);
     // The decrypted-workbook notice is for the info bar, not a message box.
     let shown: Vec<&str> = warnings.iter().map(String::as_str).filter(|w| *w != crate::io::DECRYPTED_NOTICE).collect();
     if !shown.is_empty() {
@@ -105,11 +109,16 @@ fn save(s: &mut Session, p: &Json) -> Result<Json> {
         return super::print::export_pdf(s, &json!({"path": path}));
     }
     let d = s.doc_mut()?;
-    let bytes = crate::io::save_bytes(&d.wb, &path)?;
+    // The document's own file keeps the format its content had when opened; any other path
+    // goes by its extension.
+    let kind = crate::io::FileKind::from_path(&path).or(d.content_kind.filter(|_| d.path.as_deref() == Some(path.as_str())));
+    let bytes = match kind {
+        Some(kind) => crate::io::save_bytes_as(&d.wb, &path, kind)?,
+        None => crate::io::save_bytes(&d.wb, &path)?,
+    };
     crate::io::write_file(&path, &bytes)?;
-    let kind = crate::io::FileKind::from_path(&path).unwrap_or(crate::io::FileKind::Xlsx);
     // Only a full-fidelity format clears the dirty flag and becomes the document's file.
-    if matches!(kind, crate::io::FileKind::Xlsx | crate::io::FileKind::Json) {
+    if matches!(kind, Some(crate::io::FileKind::Xlsx | crate::io::FileKind::Json)) {
         d.saved = d.wb.clone();
         d.path = Some(path.clone());
     }

crates/engine/src/cmd/forecast.rs

@@ -42,7 +42,7 @@ pub fn specs() -> Vec<CommandSpec> {
         "Forecast Sheet",
         ["Data", "Forecast"],
         None,
-        "{timeline?: \"A2:A25\", values?: \"B2:B25\" (default: the first two columns of `range`, the selection or the current region; a text first cell is the header), end?: timeline value or date text | periods?: n (default: a third of the history, at least 1; ≤10,000 and history × periods ≤ 500,000; history ≤ 10,000 rows), confidenceInterval?: bool (default true), confidence?: 0.95 or 95, seasonality?: \"auto\" | 0 (none) | 2–8,760, fillMissing?: interpolate|zeros, aggregate?: average|count|counta|max|median|min|sum, statistics?: bool, chart?: line|column} → {sheet, table, chart, history, periods}. Inserts a sheet before the active one: timeline, values, Forecast (FORECAST.ETS), Lower/Upper Confidence Bound (FORECAST.ETS.CONFINT), optional FORECAST.ETS.STAT table, and a chart.",
+        "{timeline?: \"A2:A25\", values?: \"B2:B25\" (default: the first two columns of `range`, the selection or the current region; a text first cell is the header), end?: timeline value or date text | periods?: n (default: a third of the history, at least 1; ≤10,000 and history × periods ≤ 500,000; history ≤ 10,000 rows), forecastStart?: a timeline value or date text on the history, before its last point (hindcast: the model is fit to the points before it, the forecast columns start there and run over the actuals; default and the last point: forecast after the history), confidenceInterval?: bool (default true), confidence?: 0.95 or 95, seasonality?: \"auto\" | 0 (none) | 2–8,760, fillMissing?: interpolate|zeros, aggregate?: average|count|counta|max|median|min|sum, statistics?: bool, chart?: line|column} → {sheet, table, chart, history, periods}. Inserts a sheet before the active one: timeline, values, Forecast (FORECAST.ETS), Lower/Upper Confidence Bound (FORECAST.ETS.CONFINT), optional FORECAST.ETS.STAT table, and a chart.",
         has_doc,
         forecast_sheet
     )]
@@ -223,13 +223,39 @@ fn forecast_sheet(s: &mut Session, p: &Json) -> Result<Json> {
     if !rows.iter().any(|r| matches!(r.1, Value::Number(_))) {
         return Err(EngineError::Other("There are no values to forecast.".into()));
     }
-    let end = match p.get("end") {
-        Some(Json::Number(n)) => n.as_f64(),
-        Some(Json::String(t)) if !t.trim().is_empty() => match gridcraft_core::parse::parse_input(t.trim(), sys).value {
-            Value::Number(end) => Some(end),
-            _ => return Err(bad(CMD, format!("`end` is not a number or a date: `{t}`"))),
-        },
-        _ => None,
+    let time_param = |key: &str| -> Result<Option<f64>> {
+        match p.get(key) {
+            Some(Json::Number(n)) => Ok(n.as_f64()),
+            Some(Json::String(t)) if !t.trim().is_empty() => match gridcraft_core::parse::parse_input(t.trim(), sys).value {
+                Value::Number(x) => Ok(Some(x)),
+                _ => Err(bad(CMD, format!("`{key}` is not a number or a date: `{t}`"))),
+            },
+            None | Some(Json::Null) => Ok(None),
+            Some(Json::String(_)) => Ok(None),
+            Some(_) => Err(bad(CMD, format!("`{key}` is not a number or a date"))),
+        }
+    };
+    let end = time_param("end")?;
+    // Forecast Start: the index (into `rows`) of the first forecast point, or `rows.len()` for the
+    // usual forecast after the history.
+    let fit = match time_param("forecastStart")? {
+        None => rows.len(),
+        Some(start) => {
+            let last_t = times.last().copied().unwrap_or(f64::NAN);
+            let tol = |a: f64, b: f64| (a - b).abs() <= 1e-9 * a.abs().max(b.abs()).max(1.0);
+            if tol(start, last_t) || timeline.after_last(1).is_some_and(|next| tol(start, next)) {
+                rows.len()
+            } else {
+                let i = times
+                    .iter()
+                    .position(|t| tol(*t, start))
+                    .ok_or_else(|| bad(CMD, "`forecastStart` is not on the timeline (it is a point of the history, before its last point)"))?;
+                if rows.get(..i).is_none_or(|h| h.iter().filter(|r| matches!(r.1, Value::Number(_))).count() < 2) {
+                    return Err(EngineError::Other("The forecast start needs at least two values before it to fit the forecast.".into()));
+                }
+                i
+            }
+        }
     };
     let cap = max_periods(rows.len());
     let periods = match end {
@@ -252,8 +278,9 @@ fn forecast_sheet(s: &mut Session, p: &Json) -> Result<Json> {
     // Columns: A timeline, B values, C forecast, D/E bounds.
     let n = rows.len() as u32;
     let last = n + 1; // 1-based row of the last history point
+    let fit_last = fit as u32 + 1; // 1-based row of the last point the model is fit to
     let end_row = last + periods; // 1-based row of the last forecast
-    let hist = |col: u32| format!("${0}$2:${0}${last}", col_letters(col));
+    let hist = |col: u32| format!("${0}$2:${0}${fit_last}", col_letters(col));
     let mut tail = format!("{},{}", opts.seasonality, opts.fill);
     if let Some(a) = opts.aggregate {
         tail.push_str(&format!(",{a}"));
@@ -305,22 +332,30 @@ fn forecast_sheet(s: &mut Session, p: &Json) -> Result<Json> {
                 put(&mut sheet, r, 1, v.clone(), vstyle);
             }
         }
-        // The last history point starts the forecast lines, so they join the values.
-        formula(&mut sheet, n, 2, format!("=B{last}"), vstyle);
+        // The last point the model is fit to starts the forecast lines, so they join the values.
+        let join = fit_last - 1; // 0-based row
+        formula(&mut sheet, join, 2, format!("=B{fit_last}"), vstyle);
         if opts.confidence.is_some() {
-            formula(&mut sheet, n, 3, format!("=C{last}"), vstyle);
-            formula(&mut sheet, n, 4, format!("=C{last}"), vstyle);
+            formula(&mut sheet, join, 3, format!("=C{fit_last}"), vstyle);
+            formula(&mut sheet, join, 4, format!("=C{fit_last}"), vstyle);
         }
         let (tl, vl) = (hist(0), hist(1));
+        let forecast_row = |sheet: &mut Sheet, r: u32| {
+            formula(sheet, r - 1, 2, format!("=FORECAST.ETS(A{r},{vl},{tl},{tail})"), vstyle);
+            if let Some(c) = opts.confidence {
+                let ci = format!("FORECAST.ETS.CONFINT(A{r},{vl},{tl},{c},{tail})");
+                formula(sheet, r - 1, 3, format!("=C{r}-{ci}"), vstyle);
+                formula(sheet, r - 1, 4, format!("=C{r}+{ci}"), vstyle);
+            }
+        };
+        // Hindcast: forecasts over the actuals from the start to the last history point.
+        for r in (fit_last + 1)..=last {
+            forecast_row(&mut sheet, r);
+        }
         for (k, t) in future.iter().enumerate() {
             let r = last + k as u32 + 1; // 1-based
             put(&mut sheet, r - 1, 0, Value::Number(*t), tstyle);
-            formula(&mut sheet, r - 1, 2, format!("=FORECAST.ETS(A{r},{vl},{tl},{tail})"), vstyle);
-            if let Some(c) = opts.confidence {
-                let ci = format!("FORECAST.ETS.CONFINT(A{r},{vl},{tl},{c},{tail})");
-                formula(&mut sheet, r - 1, 3, format!("=C{r}-{ci}"), vstyle);
-                formula(&mut sheet, r - 1, 4, format!("=C{r}+{ci}"), vstyle);
-            }
+            forecast_row(&mut sheet, r);
         }
         if opts.statistics {
             put(&mut sheet, 0, stats_col, Value::text("Statistic"), bold);
@@ -407,7 +442,7 @@ fn forecast_sheet(s: &mut Session, p: &Json) -> Result<Json> {
     if let Ok(d) = s.doc_mut() {
         d.sheet_selections.insert(index.min(d.sheet_selections.len()), crate::Selection::default());
     }
-    Ok(json!({"sheet": sheet_name, "table": table_name, "chart": chart_id, "history": n, "periods": periods}))
+    Ok(json!({"sheet": sheet_name, "table": table_name, "chart": chart_id, "history": n, "periods": periods, "fitted": fit}))
 }
 
 /// Forecast rows needed to reach `end` (rounded up to whole steps).
@@ -545,4 +580,39 @@ mod tests {
         s.execute("cell.set", json!({"cell": "A5", "input": "4.5"})).unwrap();
         assert!(s.execute("data.forecastSheet", json!({"range": "Sheet1!A1:B17"})).is_err());
     }
+
+    #[test]
+    fn forecast_start_hindcasts_over_the_actuals() {
+        let mut s = session_with_history(); // t = 1..16 in A2:A17
+        let r = s.execute("data.forecastSheet", json!({"range": "A1:B17", "forecastStart": 13, "periods": 2, "confidenceInterval": false})).unwrap();
+        assert_eq!(r["fitted"], 12);
+        // Fit to t = 1..12 (rows 2..13); the line joins at row 13 and forecasts rows 14..19.
+        assert_eq!(formula(&s, 0, "C13"), "B13");
+        assert_eq!(value(&s, 0, "C13"), value(&s, 0, "B13"));
+        assert_eq!(formula(&s, 0, "C14"), "FORECAST.ETS(A14,$B$2:$B$13,$A$2:$A$13,1,1)");
+        assert_eq!(formula(&s, 0, "C19"), "FORECAST.ETS(A19,$B$2:$B$13,$A$2:$A$13,1,1)");
+        // The exact seasonal series is recovered, and the actual is still shown next to it.
+        let c14 = value(&s, 0, "C14").as_f64().unwrap();
+        assert!((c14 - 39.0).abs() < 1e-6, "{c14}"); // t = 13: 10 + 26 + 3
+        assert!(value(&s, 0, "B14").as_f64().is_some());
+        // Start at the last point or one step later: as without forecastStart.
+        for start in [json!(16), json!(17)] {
+            let r = s.execute("data.forecastSheet", json!({"range": "Sheet1!A1:B17", "forecastStart": start, "periods": 2})).unwrap();
+            assert_eq!(r["fitted"], 16);
+        }
+        assert_eq!(formula(&s, 0, "C18"), "FORECAST.ETS(A18,$B$2:$B$17,$A$2:$A$17,1,1)");
+    }
+
+    #[test]
+    fn forecast_start_invalid_values_are_errors() {
+        let mut s = session_with_history();
+        let sheets = s.doc().unwrap().wb.sheets.len();
+        for bad in [json!(0), json!(2), json!(3.5), json!(18), json!(1000), json!("abc"), json!([1]), json!(1e308)] {
+            assert!(s.execute("data.forecastSheet", json!({"range": "A1:B17", "forecastStart": bad})).is_err(), "{bad}");
+        }
+        assert_eq!(s.doc().unwrap().wb.sheets.len(), sheets);
+        // Blank or null behaves like no start; empty params unchanged.
+        let r = s.execute("data.forecastSheet", json!({"range": "A1:B17", "forecastStart": ""})).unwrap();
+        assert_eq!(r["fitted"], 16);
+    }
 }

crates/engine/src/cmd/format.rs

@@ -574,6 +574,16 @@ fn merge(s: &mut Session, p: &Json, how: &str) -> Result<Json> {
                         let m = RangeRef::new(CellRef::new(row, r.start.col), CellRef::new(row, r.end.col));
                         if !m.is_single() {
                             sh.merges.push(m);
+                            // As below: only the first value of each row survives.
+                            let others: Vec<CellRef> = sh.cells.iter_range(m).map(|(c, _)| c).filter(|c| *c != m.start).collect();
+                            for c in others {
+                                if let Some(mut cell) = sh.cells.get(c).cloned() {
+                                    cell.value = gridcraft_core::Value::Empty;
+                                    cell.formula = None;
+                                    sh.set_cell(c, cell);
+                                }
+                                touched.push((sheet, c));
+                            }
                         }
                     }
                 }
@@ -953,6 +963,7 @@ fn row_height(s: &mut Session, p: &Json) -> Result<Json> {
                 e.custom = true;
             }
         }
+        cx.structural = true; // setting a height shows or hides rows: SUBTOTAL(10x) depends on it
         Ok(Json::Null)
     })
 }
@@ -992,9 +1003,7 @@ pub fn chars_to_points(c: f64) -> f64 {
     }
 }
 
-pub fn points_to_chars(px: f64) -> f64 {
-    if px <= 12.0 { (px / 12.0 * 100.0).round() / 100.0 } else { ((px - 5.0) / 7.0 * 100.0 + 0.5).trunc() / 100.0 }
-}
+pub use gridcraft_model::points_to_chars;
 
 /// Approximate text width in points for autofit (no font metrics in the engine: average glyph
 /// widths for the default font; the UI refines with real measurement when it autofits).
@@ -1069,6 +1078,7 @@ fn autofit_rows(s: &mut Session, p: &Json) -> Result<Json> {
             }
             cx.fit_rows.extend((a..=b).map(|r| (si, r)));
         }
+        cx.structural = true; // autofit reveals hidden rows: SUBTOTAL(10x) depends on it
         Ok(Json::Null)
     })
 }
@@ -1112,6 +1122,19 @@ fn hide(s: &mut Session, p: &Json, rows: bool, on: bool) -> Result<Json> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn merge_across_keeps_the_first_value_of_each_row() {
+        let mut s = crate::Session::new();
+        s.new_workbook();
+        s.execute("range.setValues", json!({"range": "A1", "values": [[1, 2], [3, 4]]})).unwrap();
+        s.execute("cell.set", json!({"cell": "D1", "input": "=SUM(A1:B2)"})).unwrap();
+        s.execute("home.mergeAcross", json!({"range": "A1:B2"})).unwrap();
+        let v = |s: &mut crate::Session, a: &str| s.execute("cell.get", json!({"cell": a})).unwrap()["value"].clone();
+        assert_eq!(v(&mut s, "B1"), Json::Null);
+        assert_eq!(v(&mut s, "B2"), Json::Null);
+        assert_eq!(v(&mut s, "D1"), json!(4.0));
+    }
+
     #[test]
     fn decimal_steps() {
         let v = gridcraft_core::Value::Number(1.5);

crates/engine/src/cmd/insert.rs

@@ -153,7 +153,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Link",
             ["Insert", "Links"],
             Some("Cmd+K"),
-            "{cell?, target: \"https://…\" | \"Sheet2!A1\" | \"mailto:…\", text?, tooltip?, remove?: bool}",
+            "{cell?, target: \"https://…\" | \"Book.xlsx\" | \"Sheet2!A1\" | \"mailto:…\", text?, tooltip?, remove?: bool}",
             has_doc,
             insert_link
         ),
@@ -240,7 +240,7 @@ fn insert_table(s: &mut Session, p: &Json) -> Result<Json> {
     let name = str_param(p, "name")
         .map(str::to_string)
         .unwrap_or_else(|| (1..).map(|n| format!("Table{n}")).find(|n| d.wb.table(n).is_none()).unwrap_or_else(|| "Table".into()));
-    if name.is_empty() || name.contains(' ') || name.chars().next().is_some_and(|c| c.is_ascii_digit()) || CellRef::parse(&name).is_some() {
+    if !valid_table_name(&name) {
         return Err(EngineError::Other("The name that you entered is not valid.".into()));
     }
     if d.wb.table(&name).is_some() || d.wb.names.iter().any(|n| n.name.eq_ignore_ascii_case(&name)) {
@@ -349,6 +349,9 @@ fn table_flag(s: &mut Session, p: &Json, which: &str) -> Result<Json> {
             "totals" => {
                 let v = on.unwrap_or(!t.totals_row);
                 if v != t.totals_row {
+                    if v && t.range.end.row.saturating_add(1) >= MAX_ROWS {
+                        return Err(EngineError::Other("There's no room below the table for the total row.".into()));
+                    }
                     t.totals_row = v;
                     if v {
                         t.range.end.row += 1;
@@ -448,14 +451,19 @@ fn table_style(s: &mut Session, p: &Json) -> Result<Json> {
     })
 }
 
+/// Table names follow the Microsoft name rules, as the xlsx writer does: letters, digits, `_` and `.`,
+/// starting with a letter, `_` or `\`. Anything else (a hyphen, say) would read as an operator inside a
+/// structured reference, and the writer would rename the table on save.
+fn valid_table_name(name: &str) -> bool {
+    name.starts_with(|c: char| c.is_alphabetic() || c == '_' || c == '\\')
+        && CellRef::parse(name).is_none()
+        && name.chars().enumerate().all(|(i, c)| c.is_alphanumeric() || c == '_' || c == '.' || (i == 0 && c == '\\'))
+}
+
 fn table_rename(s: &mut Session, p: &Json) -> Result<Json> {
     let (si, ti) = find_table(s, p)?;
     let name = str_param(p, "name").ok_or_else(|| bad("table.rename", "missing `name`"))?.to_string();
-    if name.is_empty()
-        || name.contains(' ')
-        || name.chars().next().is_some_and(|c| c.is_ascii_digit())
-        || gridcraft_core::CellRef::parse(&name).is_some()
-    {
+    if !valid_table_name(&name) {
         return Err(EngineError::Other("The name that you entered is not valid.".into()));
     }
     if s.doc()?.wb.table(&name).is_some_and(|x| x != (si, ti)) {
@@ -470,6 +478,8 @@ fn table_rename(s: &mut Session, p: &Json) -> Result<Json> {
         for i in 0..cx.wb.sheets.len() {
             let keys: Vec<(CellRef, std::sync::Arc<Formula>)> =
                 cx.wb.sheets.get(i).map(|s| s.cells.iter().filter_map(|(c, x)| x.formula.clone().map(|f| (c, f))).collect()).unwrap_or_default();
+            // A bare name that is also a defined name resolves to the defined name, so it is not the table.
+            let shadowed = cx.wb.name(&old, i).is_some();
             let Some(sh) = cx.wb.sheet_mut(i) else { continue };
             for (c, f) in keys {
                 let Some(e) = f.expr() else { continue };
@@ -478,7 +488,7 @@ fn table_rename(s: &mut Session, p: &Json) -> Result<Json> {
                         st.table = name.clone();
                         gridcraft_formula::Expr::Struct(st)
                     }
-                    gridcraft_formula::Expr::Name(n) if n.eq_ignore_ascii_case(&old) => gridcraft_formula::Expr::Name(name.clone()),
+                    gridcraft_formula::Expr::Name(n) if !shadowed && n.eq_ignore_ascii_case(&old) => gridcraft_formula::Expr::Name(name.clone()),
                     o => o,
                 });
                 if let Some(cell) = sh.cells.get_mut(c) {
@@ -1156,6 +1166,7 @@ fn insert_link(s: &mut Session, p: &Json) -> Result<Json> {
     };
     let text = str_param(p, "text").map(str::to_string);
     let tooltip = str_param(p, "tooltip").map(str::to_string);
+    let external = links_outside(&s.doc()?.wb, sheet, &target);
     edit(s, |cx| {
         let link_style = cx.wb.styles.derive(cx.wb.sheet(sheet).map(|sh| sh.style_id(at)).unwrap_or_default(), |st| {
             st.font.color = Color::Theme(10, 0);
@@ -1167,12 +1178,30 @@ fn insert_link(s: &mut Session, p: &Json) -> Result<Json> {
         } else {
             sh.set_style(at, link_style);
         }
-        sh.hyperlinks.insert(at, Hyperlink { target: target.clone(), tooltip: tooltip.clone() });
+        sh.hyperlinks.insert(at, Hyperlink { target: target.clone(), tooltip: tooltip.clone(), external });
         cx.touch(sheet, at);
         Ok(Json::Null)
     })
 }
 
+/// Sorts a link target as the two pages of Excel's Insert Hyperlink dialog do: "Place in This
+/// Document" is a sheet reference, a defined name or `#…`; anything else ("Existing File or Web
+/// Page") is outside the workbook and saved as a relationship.
+fn links_outside(wb: &Workbook, sheet: usize, target: &str) -> bool {
+    let t = target.trim();
+    if t.starts_with('#') || wb.name(t, sheet).is_some() || wb.table(t).is_some() {
+        return false;
+    }
+    let (on, body) = split_sheet(t);
+    // Sheet names can't hold `: \ / ? * [ ]`, so `https://…!A1` or `C:\…!A1` is no sheet reference,
+    // and `Book.xlsx#Sheet1!A1` is a place in another file unless a sheet has that name.
+    let on_sheet = on.is_none_or(|name| {
+        wb.sheets.iter().any(|s| s.name.eq_ignore_ascii_case(&name))
+            || (!name.is_empty() && !name.contains([':', '\\', '/', '?', '*', '[', ']', '#']))
+    });
+    !(on_sheet && RangeRef::parse(body).is_some())
+}
+
 fn comment(s: &mut Session, p: &Json, threaded: bool) -> Result<Json> {
     let sheet = target_sheet(s, p)?;
     let at = cell_param_on(s, p, "cell", sheet)?.unwrap_or(s.doc()?.selection.active);
@@ -1420,20 +1449,20 @@ fn manage_cf(s: &mut Session, p: &Json) -> Result<Json> {
     }
     edit(s, |cx| {
         let sh = cx.sheet_mut(sheet)?;
-        let n = sh.cond_formats.len();
+        // The count is taken again after each step: a delete shortens the list.
         if let Some(i) = u32_param(p, "delete").map(|v| v as usize)
-            && i < n
+            && i < sh.cond_formats.len()
         {
             sh.cond_formats.remove(i);
         }
         if let Some(i) = u32_param(p, "moveUp").map(|v| v as usize)
             && i > 0
-            && i < n
+            && i < sh.cond_formats.len()
         {
             sh.cond_formats.swap(i, i - 1);
         }
         if let Some(i) = u32_param(p, "moveDown").map(|v| v as usize)
-            && i + 1 < n
+            && i + 1 < sh.cond_formats.len()
         {
             sh.cond_formats.swap(i, i + 1);
         }
@@ -1466,3 +1495,23 @@ fn insert_icon(s: &mut Session, p: &Json) -> Result<Json> {
         Ok(json!({"shape": id}))
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn manage_rules_delete_then_move() {
+        let mut s = Session::new();
+        s.new_workbook();
+        for v in ["1", "2"] {
+            let rule = json!({"type": "cellIs", "operator": "greaterThan", "value": v, "preset": "lightRedFill"});
+            s.execute("home.conditionalFormat", json!({"range": "A1:A3", "rule": rule})).unwrap();
+        }
+        // Deleting first left two rules' worth of indices for the move: it panicked.
+        s.execute("home.manageRules", json!({"delete": 0, "moveUp": 1})).unwrap();
+        s.execute("home.manageRules", json!({"delete": 0, "moveDown": 0})).unwrap();
+        let rules = s.execute("home.manageRules", json!({})).unwrap();
+        assert_eq!(rules["rules"].as_array().map(Vec::len), Some(0));
+    }
+}

crates/engine/src/cmd/pivot.rs

@@ -87,7 +87,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Move Field",
             [],
             None,
-            "{pivot?, field, from: rows|columns|values|filters, to: rows|columns|values|filters, position?: index, replace?}",
+            "{pivot?, field (\"Σ Values\" moves the value fields between rows and columns; in columns it stays after the last field), from: rows|columns|values|filters, to: rows|columns|values|filters, position?: index, replace?}",
             has_doc,
             move_field
         ),
@@ -333,6 +333,71 @@ fn in_axes(pt: &PivotTable, field: &str) -> bool {
     pt.rows.iter().chain(pt.columns.iter()).any(|f| f.source_col.eq_ignore_ascii_case(field))
 }
 
+/// Name of the Σ Values pseudo-field (where the value fields sit when there are two or more).
+const VALUES_FIELD: &str = "Σ Values";
+
+/// Whether `field` names Σ Values: `Σ Values`, or `Values` unless a source field has that name.
+fn is_values_field(src: &pv::Source, field: &str) -> bool {
+    let f = field.trim();
+    f == VALUES_FIELD || (f.eq_ignore_ascii_case("values") && src.col(f).is_none())
+}
+
+/// Keeps Σ Values in place after a field left (`inserted` false) or arrived at index `i` of
+/// Rows (`rows`) or Columns.
+fn shift_values(pt: &mut PivotTable, rows: bool, i: usize, inserted: bool) {
+    if pt.values_on_rows != rows {
+        return;
+    }
+    let Some(p) = pt.values_position else { return };
+    // Σ Values stays just ahead of the field it preceded.
+    let p = match inserted {
+        true if i <= p => p + 1,
+        false if i < p => p - 1,
+        _ => p,
+    };
+    let n = if rows { pt.rows.len() } else { pt.columns.len() };
+    pt.values_position = (p < n).then_some(p);
+}
+
+/// Takes `field` out of Rows and Columns (Σ Values keeps its place); returns its first entry.
+fn take_from_axes(pt: &mut PivotTable, field: &str) -> Option<PivotField> {
+    let mut first = None;
+    for rows in [true, false] {
+        loop {
+            let list = if rows { &mut pt.rows } else { &mut pt.columns };
+            let Some(i) = list.iter().position(|f| f.source_col.eq_ignore_ascii_case(field)) else { break };
+            let f = list.remove(i);
+            shift_values(pt, rows, i, false);
+            first.get_or_insert(f);
+        }
+    }
+    first
+}
+
+/// Inserts `f` into Rows (`rows`) or Columns at `position` (default: the end).
+fn insert_axis_field(pt: &mut PivotTable, rows: bool, f: PivotField, position: Option<usize>) {
+    let list = if rows { &mut pt.rows } else { &mut pt.columns };
+    let at = position.unwrap_or(list.len()).min(list.len());
+    list.insert(at, f);
+    shift_values(pt, rows, at, true);
+}
+
+/// Moves Σ Values between Rows and Columns, or within Rows, to `position` (default: the end).
+/// In Columns it always comes after the last column field: the column layout doesn't place it
+/// anywhere else yet.
+fn move_values_field(cmd: &str, pt: &mut PivotTable, from: &str, to: &str, position: Option<usize>) -> Result<Json> {
+    let current = if pt.values_on_rows { "rows" } else { "columns" };
+    if from != current {
+        return Err(bad(cmd, format!("`{VALUES_FIELD}` isn't in the {from} area")));
+    }
+    if !matches!(to, "rows" | "columns") {
+        return Err(other("The field you are moving cannot be placed in that PivotTable area."));
+    }
+    pt.values_on_rows = to == "rows";
+    pt.values_position = position.filter(|p| pt.values_on_rows && *p < pt.rows.len());
+    Ok(json!({"field": VALUES_FIELD, "to": to}))
+}
+
 /// The canonical source field name for `field`.
 fn canonical(cmd: &str, src: &pv::Source, field: &str) -> Result<String> {
     src.col(field).and_then(|c| src.headers.get(c).cloned()).ok_or_else(|| bad(cmd, format!("no field `{field}` in the source data")))
@@ -384,21 +449,11 @@ fn add_to_area(
             if pt.rows.len() + pt.columns.len() >= pv::MAX_AXIS_FIELDS && !in_axes(pt, &field) {
                 return Err(other(format!("A PivotTable can have at most {} row and column fields.", pv::MAX_AXIS_FIELDS)));
             }
-            let existing = pt
-                .rows
-                .iter()
-                .chain(pt.columns.iter())
-                .find(|f| f.source_col.eq_ignore_ascii_case(&field))
-                .cloned()
-                .unwrap_or_else(|| PivotField { source_col: field.clone(), ..Default::default() });
-            pt.rows.retain(|f| !f.source_col.eq_ignore_ascii_case(&field));
-            pt.columns.retain(|f| !f.source_col.eq_ignore_ascii_case(&field));
+            let existing = take_from_axes(pt, &field).unwrap_or_else(|| PivotField { source_col: field.clone(), ..Default::default() });
             // A report filter that selects nothing in particular goes away; a selection stays
             // as the field's hidden items.
             pt.filters.retain(|f| !(f.source_col.eq_ignore_ascii_case(&field) && f.selected.is_none()));
-            let list = if area == "rows" { &mut pt.rows } else { &mut pt.columns };
-            let at = position.unwrap_or(list.len()).min(list.len());
-            list.insert(at, existing);
+            insert_axis_field(pt, area == "rows", existing, position);
         }
         "values" => {
             if pt.values.len() >= pv::MAX_VALUE_FIELDS {
@@ -421,8 +476,7 @@ fn add_to_area(
             pt.values.insert(at, v);
         }
         _ => {
-            pt.rows.retain(|f| !f.source_col.eq_ignore_ascii_case(&field));
-            pt.columns.retain(|f| !f.source_col.eq_ignore_ascii_case(&field));
+            take_from_axes(pt, &field);
             let existing = pt.filters.iter().position(|f| f.source_col.eq_ignore_ascii_case(&field));
             let entry = match existing {
                 Some(i) => pt.filters.remove(i),
@@ -439,12 +493,14 @@ fn add_to_area(
 fn remove_from_area(cmd: &str, pt: &mut PivotTable, field: &str, area: &str) -> Result<String> {
     match area {
         "rows" | "columns" => {
-            let list = if area == "rows" { &mut pt.rows } else { &mut pt.columns };
+            let rows = area == "rows";
+            let list = if rows { &mut pt.rows } else { &mut pt.columns };
             let i = list
                 .iter()
                 .position(|f| f.source_col.eq_ignore_ascii_case(field))
                 .ok_or_else(|| bad(cmd, format!("`{field}` isn't in the {area} area")))?;
             let f = list.remove(i);
+            shift_values(pt, rows, i, false);
             pt.filters.retain(|x| !x.source_col.eq_ignore_ascii_case(&f.source_col));
             Ok(f.source_col)
         }
@@ -699,6 +755,8 @@ fn pivot_json(wb: &Workbook, si: usize, pt: &PivotTable) -> Json {
         "style": pt.style,
         "showHeaders": pt.show_headers,
         "calculatedFields": pt.calculated_fields.iter().map(|c| json!({"name": c.name, "formula": c.formula})).collect::<Vec<_>>(),
+        "valuesOnRows": pt.values_on_rows,
+        "valuesPosition": pt.values_position,
     })
 }
 
@@ -890,18 +948,22 @@ fn move_field(s: &mut Session, p: &Json) -> Result<Json> {
     let to = area_param(C, str_param(p, "to"))?;
     let pos = position_param(p);
     update(s, p, |pt, src, _| {
+        if is_values_field(src, &field) {
+            return move_values_field(C, pt, from, to, pos);
+        }
         if from == to {
             // Reorder within the area.
             match from {
                 "rows" | "columns" => {
-                    let list = if from == "rows" { &mut pt.rows } else { &mut pt.columns };
+                    let rows = from == "rows";
+                    let list = if rows { &mut pt.rows } else { &mut pt.columns };
                     let i = list
                         .iter()
                         .position(|f| f.source_col.eq_ignore_ascii_case(&field))
                         .ok_or_else(|| bad(C, format!("`{field}` isn't in the {from} area")))?;
                     let f = list.remove(i);
-                    let at = pos.unwrap_or(list.len()).min(list.len());
-                    list.insert(at, f);
+                    shift_values(pt, rows, i, false);
+                    insert_axis_field(pt, rows, f, pos);
                 }
                 "values" => {
                     let i = pt
@@ -1270,8 +1332,20 @@ fn change_source(s: &mut Session, p: &Json) -> Result<Json> {
             }
             ok
         };
-        pt.rows.retain(|f| keep(&f.source_col, &mut dropped));
-        pt.columns.retain(|f| keep(&f.source_col, &mut dropped));
+        // Axis fields leave one by one so Σ Values keeps its place among the rest.
+        for rows in [true, false] {
+            let mut i = 0;
+            loop {
+                let list = if rows { &mut pt.rows } else { &mut pt.columns };
+                let Some(f) = list.get(i) else { break };
+                if keep(&f.source_col, &mut dropped) {
+                    i += 1;
+                } else {
+                    list.remove(i);
+                    shift_values(pt, rows, i, false);
+                }
+            }
+        }
         pt.values.retain(|f| keep(&f.source_col, &mut dropped));
         pt.filters.retain(|f| keep(&f.source_col, &mut dropped));
         Ok(json!({"source": source, "dropped": dropped}))
@@ -1722,6 +1796,167 @@ mod tests {
         assert_eq!(text(&s, "A5"), "Apples");
     }
 
+    #[test]
+    fn values_on_rows_layouts() {
+        let mut s = sales();
+        s.execute("insert.pivotTable", json!({"rows": ["Region"], "values": ["Sales", "Units"]})).unwrap();
+        assert_eq!(text(&s, "C3"), "Sum of Units");
+        // Σ Values after Region: each region holds one line per value field.
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "rows"})).unwrap();
+        let p = pt(&s);
+        assert!(p.values_on_rows);
+        assert_eq!(p.values_position, None);
+        let r = p.last_range.unwrap();
+        assert_eq!(r.width(), 2);
+        // header + 3 × (region + 2 values) + 2 grand totals
+        assert_eq!(r.height(), 1 + 9 + 2);
+        assert_eq!(text(&s, "A4"), "East");
+        assert_eq!(val(&s, "B4"), Value::Empty);
+        assert_eq!(text(&s, "A5"), "Sum of Sales");
+        assert_eq!(val(&s, "B5"), Value::Number(415.0));
+        assert_eq!(text(&s, "A6"), "Sum of Units");
+        assert_eq!(val(&s, "B6"), Value::Number(33.0));
+        assert_eq!(text(&s, "A13"), "Total Sum of Sales");
+        assert_eq!(val(&s, "B13"), Value::Number(TOTAL));
+        assert_eq!(text(&s, "A14"), "Total Sum of Units");
+        assert_eq!(val(&s, "B14"), Value::Number(72.0));
+        // Tabular, no column field: "Total" heads the data column, as Excel saves it.
+        s.execute("pivot.layout", json!({"layout": "tabular"})).unwrap();
+        assert_eq!(text(&s, "A3"), "Region");
+        assert_eq!(text(&s, "B3"), "Values");
+        assert_eq!(text(&s, "C3"), "Total");
+        s.execute("pivot.layout", json!({"layout": "compact"})).unwrap();
+        // Σ Values before Region: the value fields are the outer items.
+        s.execute("pivot.moveField", json!({"field": "Values", "from": "rows", "to": "rows", "position": 0})).unwrap();
+        assert_eq!(pt(&s).values_position, Some(0));
+        assert_eq!(text(&s, "A4"), "Sum of Sales");
+        assert_eq!(val(&s, "B4"), Value::Empty);
+        assert_eq!(text(&s, "A5"), "East");
+        assert_eq!(val(&s, "B5"), Value::Number(415.0));
+        assert_eq!(text(&s, "A8"), "Sum of Units");
+        assert_eq!(text(&s, "A9"), "East");
+        assert_eq!(val(&s, "B9"), Value::Number(33.0));
+        assert_eq!(text(&s, "A12"), "Total Sum of Sales");
+        assert_eq!(val(&s, "B13"), Value::Number(72.0));
+        // Adding a row field in front keeps Σ Values ahead of Region.
+        s.execute("pivot.addField", json!({"field": "Product", "area": "rows", "position": 0})).unwrap();
+        assert_eq!(pt(&s).values_position, Some(1));
+        s.execute("pivot.removeField", json!({"field": "Product", "area": "rows"})).unwrap();
+        assert_eq!(pt(&s).values_position, Some(0));
+        // No row field: one line per value field and no grand total.
+        s.execute("pivot.removeField", json!({"field": "Region", "area": "rows"})).unwrap();
+        let r = pt(&s).last_range.unwrap();
+        assert_eq!(r.height(), 1 + 2);
+        assert_eq!(text(&s, "A4"), "Sum of Sales");
+        assert_eq!(val(&s, "B4"), Value::Number(TOTAL));
+        assert_eq!(text(&s, "A5"), "Sum of Units");
+        assert_eq!(val(&s, "B5"), Value::Number(72.0));
+        // Back to Columns.
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "rows", "to": "columns"})).unwrap();
+        assert!(!pt(&s).values_on_rows);
+        assert_eq!(text(&s, "A3"), "Sum of Sales");
+        assert_eq!(text(&s, "B3"), "Sum of Units");
+        assert!(s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "filters"})).is_err());
+        assert!(s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "rows", "to": "columns"})).is_err());
+    }
+
+    #[test]
+    fn collapsed_item_puts_values_in_the_values_column() {
+        let mut s = sales();
+        s.execute("insert.pivotTable", json!({"rows": ["Region", "Product"], "values": ["Sales", "Units"]})).unwrap();
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "rows"})).unwrap();
+        s.execute("pivot.collapse", json!({"field": "Region", "items": ["East"]})).unwrap();
+        for layout in ["tabular", "outline"] {
+            s.execute("pivot.layout", json!({"layout": layout})).unwrap();
+            assert_eq!(text(&s, "C3"), "Values", "{layout}");
+            let east = (4..20).find(|r| text(&s, &format!("A{r}")) == "East").unwrap();
+            let first = if layout == "tabular" { east } else { east + 1 };
+            assert_eq!(text(&s, &format!("B{first}")), "", "{layout}");
+            assert_eq!(text(&s, &format!("C{first}")), "Sum of Sales", "{layout}");
+            assert_eq!(val(&s, &format!("D{first}")), Value::Number(415.0), "{layout}");
+            assert_eq!(text(&s, &format!("C{}", first + 1)), "Sum of Units", "{layout}");
+        }
+    }
+
+    #[test]
+    fn values_stay_last_in_columns() {
+        let mut s = sales();
+        s.execute("insert.pivotTable", json!({"rows": ["Product"], "columns": ["Region"], "values": ["Sales", "Units"]})).unwrap();
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "columns", "position": 0})).unwrap();
+        let p = pt(&s);
+        assert!(!p.values_on_rows);
+        assert_eq!(p.values_position, None);
+        // Σ Values to Rows and back with a position: still last in Columns.
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "rows"})).unwrap();
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "rows", "to": "columns", "position": 0})).unwrap();
+        assert_eq!(pt(&s).values_position, None);
+        assert_eq!(text(&s, "B5"), "Sum of Sales");
+        assert_eq!(text(&s, "C5"), "Sum of Units");
+    }
+
+    #[test]
+    fn change_source_keeps_values_ahead_of_its_field() {
+        let mut s = sales();
+        s.execute("insert.pivotTable", json!({"rows": ["Region", "Product"], "values": ["Sales", "Units"]})).unwrap();
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "rows", "position": 1})).unwrap();
+        // The new source has no Region: Σ Values stays ahead of Product.
+        s.execute("pivot.changeSource", json!({"source": "Sheet1!B1:E13"})).unwrap();
+        let p = pt(&s);
+        assert_eq!(p.rows.len(), 1);
+        assert_eq!(p.values_position, Some(0));
+        assert_eq!(text(&s, "A4"), "Sum of Sales");
+        assert_eq!(text(&s, "A5"), "Apples");
+    }
+
+    #[test]
+    fn values_on_rows_between_row_fields() {
+        let mut s = sales();
+        s.execute("insert.pivotTable", json!({"rows": ["Region", "Product"], "values": ["Sales", "Units"]})).unwrap();
+        s.execute("pivot.moveField", json!({"field": "Σ Values", "from": "columns", "to": "rows", "position": 1})).unwrap();
+        // Compact: East, then per value field its products, then per-value subtotals of East.
+        assert_eq!(text(&s, "A4"), "East");
+        assert_eq!(text(&s, "A5"), "Sum of Sales");
+        assert_eq!(text(&s, "A6"), "Apples");
+        assert_eq!(val(&s, "B6"), Value::Number(160.0));
+        assert_eq!(text(&s, "A9"), "Sum of Units");
+        assert_eq!(text(&s, "A10"), "Apples");
+        assert_eq!(val(&s, "B10"), Value::Number(16.0));
+        assert_eq!(text(&s, "A13"), "East Sum of Sales");
+        assert_eq!(val(&s, "B13"), Value::Number(415.0));
+        assert_eq!(text(&s, "A14"), "East Sum of Units");
+        assert_eq!(val(&s, "B14"), Value::Number(33.0));
+        let d = s.doc().unwrap();
+        let sh = d.wb.active().unwrap();
+        assert_eq!(d.wb.styles.get(sh.style_id(CellRef::parse("A5").unwrap())).align.indent, 1);
+        assert_eq!(d.wb.styles.get(sh.style_id(CellRef::parse("A6").unwrap())).align.indent, 2);
+        // Outline: one column per level, "Values" heads the Σ Values column.
+        s.execute("pivot.layout", json!({"layout": "outline"})).unwrap();
+        assert_eq!(pt(&s).last_range.unwrap().width(), 4);
+        assert_eq!(text(&s, "A3"), "Region");
+        assert_eq!(text(&s, "B3"), "Values");
+        assert_eq!(text(&s, "C3"), "Product");
+        assert_eq!(text(&s, "B5"), "Sum of Sales");
+        assert_eq!(text(&s, "C6"), "Apples");
+        assert_eq!(val(&s, "D6"), Value::Number(160.0));
+        // Tabular: labels start on their parent's row; totals per value field below each group.
+        s.execute("pivot.layout", json!({"layout": "tabular"})).unwrap();
+        assert_eq!(text(&s, "A4"), "East");
+        assert_eq!(text(&s, "B4"), "Sum of Sales");
+        assert_eq!(text(&s, "C4"), "Apples");
+        assert_eq!(val(&s, "D4"), Value::Number(160.0));
+        assert_eq!(text(&s, "B7"), "Sum of Units");
+        assert_eq!(text(&s, "C7"), "Apples");
+        assert_eq!(val(&s, "D7"), Value::Number(16.0));
+        assert_eq!(text(&s, "A10"), "East Sum of Sales");
+        assert_eq!(val(&s, "D10"), Value::Number(415.0));
+        assert_eq!(text(&s, "A11"), "East Sum of Units");
+        let r = pt(&s).last_range.unwrap();
+        let last = r.end.row + 1;
+        assert_eq!(text(&s, &format!("A{}", last - 1)), "Total Sum of Sales");
+        assert_eq!(text(&s, &format!("A{last}")), "Total Sum of Units");
+        assert_eq!(val(&s, &format!("D{last}")), Value::Number(72.0));
+    }
+
     #[test]
     fn refresh_after_source_edits() {
         let mut s = sales();
@@ -2039,4 +2274,38 @@ mod tests {
         assert!(e.contains("field name is not valid"), "{e}");
         assert!(s.execute("insert.pivotTable", json!({"source": "NoSuchTable"})).is_err());
     }
+
+    #[test]
+    fn too_many_value_columns_are_refused() {
+        let mut s = Session::new();
+        s.new_workbook();
+        let mut records: Vec<Json> = vec![json!(["Cat", "Sub", "V"])];
+        for r in 0..64 {
+            for c in 0..64 {
+                records.push(json!([format!("c{r}"), format!("s{c}"), 1.0]));
+            }
+        }
+        s.execute("range.setValues", json!({"range": "A1", "values": records})).unwrap();
+        let req = |n: usize| {
+            let values: Vec<Json> = (0..n).map(|_| json!({"field": "V"})).collect();
+            json!({"source": "A1:C4097", "rows": ["Cat"], "columns": ["Sub"], "values": values})
+        };
+        let e = s.execute("insert.pivotTable", req(256)).unwrap_err().to_string();
+        assert!(e.contains("will not fit"), "{e}");
+        assert!(s.execute("insert.pivotTable", req(128)).is_ok());
+    }
+
+    #[test]
+    fn collapsed_column_items_count_as_one_column_group() {
+        let mut s = Session::new();
+        s.new_workbook();
+        let mut records: Vec<Json> = vec![json!(["Grp", "Sub", "V"])];
+        records.extend((0..64).map(|c| json!(["g", format!("s{c}"), 1.0])));
+        s.execute("range.setValues", json!({"range": "A1", "values": records})).unwrap();
+        let values: Vec<Json> = (0..256).map(|_| json!({"field": "V"})).collect();
+        s.execute("insert.pivotTable", json!({"source": "A1:C65", "columns": ["Grp"], "values": values})).unwrap();
+        s.execute("pivot.collapse", json!({"field": "Grp"})).unwrap();
+        // 64 Sub items under the collapsed "g" show as one column group: (1 + grand total) x 256 columns fit.
+        s.execute("pivot.addField", json!({"field": "Sub", "area": "columns"})).unwrap();
+    }
 }

crates/engine/src/cmd/print.rs

@@ -391,7 +391,7 @@ pub struct HfContext {
 
 /// Today's date and the current time as headers and footers show them (`&D`, `&T`).
 pub fn hf_date_time(wb: &Workbook) -> (String, String) {
-    let now = gridcraft_calc::now_serial();
+    let now = gridcraft_core::date::serial_in_system(wb.date_system, gridcraft_calc::now_serial());
     let date = crate::display::format(&Value::Number(now.floor()), "m/d/yyyy", wb).text;
     let time = crate::display::format(&Value::Number(now), "h:mm AM/PM", wb).text;
     (date, time)
@@ -1765,6 +1765,14 @@ mod tests {
         }
     }
 
+    #[test]
+    fn header_footer_date_follows_the_workbook_date_system() {
+        let mut wb = Workbook::new();
+        let date_1900 = hf_date_time(&wb).0;
+        wb.date_system = gridcraft_core::DateSystem::D1904;
+        assert_eq!(hf_date_time(&wb).0, date_1900);
+    }
+
     #[test]
     fn header_footer_section_edits_are_undoable_and_views_are_per_sheet() {
         let mut s = s();
@@ -2046,6 +2054,23 @@ mod tests {
         assert!(s.execute("file.exportPdf", json!({})).is_ok());
     }
 
+    #[test]
+    fn export_pdf_without_a_path_returns_bytes_and_never_opens_a_dialog() {
+        let mut s = s();
+        for params in [json!({}), json!({"path": ""}), json!({"path": null})] {
+            let r = s.execute("file.exportPdf", params).unwrap();
+            assert!(r.get("path").is_none(), "no file is written without a path");
+            let bytes = crate::io::base64_decode(r["base64"].as_str().unwrap()).unwrap();
+            assert!(bytes.starts_with(b"%PDF-"));
+        }
+        assert!(s.take_ui_requests().is_empty(), "a programmatic call never queues a dialog");
+        // Headless callers (CLI, MCP) get the same bytes, not an error.
+        assert!(s.execute_headless("file.exportPdf", json!({})).is_ok());
+        // With no workbook open it is a clear error, not a panic.
+        let mut none = Session::new();
+        assert!(none.execute("file.exportPdf", json!({})).is_err());
+    }
+
     #[test]
     fn bands_unit() {
         let b = bands(0, 9, |_| 10.0, |_| 35.0, &[], 100);

crates/engine/src/cmd/sheet.rs

@@ -249,10 +249,14 @@ fn cancel_copy_mode(s: &mut Session) {
 
 fn insert_lines(s: &mut Session, p: &Json, axis: Axis) -> Result<Json> {
     let (at, count) = lines(s, p, axis)?;
+    let limit = if axis == Axis::Rows { MAX_ROWS } else { MAX_COLS };
+    if at.checked_add(count).is_none_or(|end| end > limit) {
+        let cmd = if axis == Axis::Rows { "home.insertRows" } else { "home.insertColumns" };
+        return Err(bad(cmd, "the inserted lines would extend past the end of the worksheet"));
+    }
     check_lines_protection(s, p, axis, at, count, true)?;
     let sheet = target_sheet(s, p)?;
     // Refuse to push data off the sheet.
-    let limit = if axis == Axis::Rows { MAX_ROWS } else { MAX_COLS };
     if let Some(u) = s.doc()?.wb.sheet(sheet).and_then(|sh| sh.used_range()) {
         let last = if axis == Axis::Rows { u.end.row } else { u.end.col };
         if last >= at && last as u64 + count as u64 >= limit as u64 {
@@ -290,6 +294,9 @@ fn insert_lines(s: &mut Session, p: &Json, axis: Axis) -> Result<Json> {
 
 fn delete_lines(s: &mut Session, p: &Json, axis: Axis) -> Result<Json> {
     let (at, count) = lines(s, p, axis)?;
+    let limit = if axis == Axis::Rows { MAX_ROWS } else { MAX_COLS };
+    // Deleting past the last line only removes up to the end of the worksheet.
+    let count = count.min(limit.saturating_sub(at)).max(1);
     check_lines_protection(s, p, axis, at, count, false)?;
     let sheet = target_sheet(s, p)?;
     let out = edit(s, |cx| {

crates/engine/src/cmd/spelling.rs

@@ -64,7 +64,14 @@ fn known(s: &Session, w: &str) -> bool {
     false
 }
 
+/// Longest word we generate suggestions for. Candidate text grows with the square of the word length, so longer
+/// tokens (no real word is this long) get no suggestions instead of an unbounded allocation.
+const MAX_SUGGEST_LEN: usize = 64;
+
 fn edits1(w: &str) -> Vec<String> {
+    if w.chars().count() > MAX_SUGGEST_LEN {
+        return Vec::new();
+    }
     let chars: Vec<char> = w.chars().collect();
     let mut out = Vec::new();
     let letters = "abcdefghijklmnopqrstuvwxyz";
@@ -177,3 +184,16 @@ fn thesaurus(_: &mut Session, p: &Json) -> Result<Json> {
     related.truncate(20);
     Ok(json!(related))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn edits1_is_capped_for_very_long_words() {
+        assert_eq!(edits1("helo").len(), 54 * 4 + 25);
+        assert_eq!(edits1(&"a".repeat(MAX_SUGGEST_LEN)).len(), 54 * MAX_SUGGEST_LEN + 25);
+        assert!(edits1(&"a".repeat(MAX_SUGGEST_LEN + 1)).is_empty());
+        assert!(edits1(&"a".repeat(1_000_000)).is_empty());
+    }
+}

crates/engine/src/fill.rs

@@ -6,6 +6,7 @@ use std::sync::Arc;
 use gridcraft_core::date::{MONTHS, WEEKDAYS, datetime_from_serial, days_in_month, serial_from_ymd};
 use gridcraft_core::{CellRef, RangeRef, Value};
 use gridcraft_model::{Cell, Formula};
+use gridcraft_numfmt::{FormatKind, NumberFormat};
 
 use crate::Result;
 use crate::cmd::Ctx;
@@ -65,21 +66,25 @@ pub fn fill(cx: &mut Ctx, sheet: usize, src: RangeRef, target: RangeRef, mode: F
                 if forward { (src.end.col + 1..=target.end.col).collect() } else { (target.start.col..src.start.col).rev().collect() };
             cols.into_iter().map(|c| CellRef::new(lane, c)).collect()
         };
+        let fmt = |c: &(CellRef, Option<Cell>)| cx.wb.styles.get(c.1.as_ref().map(|c| c.style).unwrap_or_default()).num_fmt.as_str();
         let pattern = if matches!(mode, FillMode::Series | FillMode::Alternate) {
-            let detected = Pattern::detect(
-                &src_cells,
-                &custom,
-                cx.wb.date_system,
-                cx.wb.styles.get(src_cells.first().and_then(|c| c.1.as_ref()).map(|c| c.style).unwrap_or_default()).num_fmt.as_str(),
-            );
+            let detected = Pattern::detect(&src_cells, &custom, cx.wb.date_system, src_cells.first().map(fmt).unwrap_or_default());
             if mode == FillMode::Alternate { detected.alternate(&src_cells) } else { detected }
         } else {
             Pattern::Copy
         };
+        // A source with no common pattern (`Product 1`, `On backorder`): each cell continues its
+        // own series, one step per repeat of the source.
+        let per_cell: Vec<Pattern> = if mode == FillMode::Series && matches!(pattern, Pattern::Copy) && src_cells.len() > 1 {
+            src_cells.iter().map(|c| Pattern::detect(std::slice::from_ref(c), &custom, cx.wb.date_system, fmt(c))).collect()
+        } else {
+            Vec::new()
+        };
         for (k, t) in targets.iter().enumerate() {
             let step = k as i64 + 1;
             let idx = k % src_cells.len().max(1);
-            let (sc, scell) = src_cells.get(if forward { idx } else { src_cells.len() - 1 - idx }).cloned().unwrap_or((src.start, None));
+            let src_i = if forward { idx } else { src_cells.len() - 1 - idx };
+            let (sc, scell) = src_cells.get(src_i).cloned().unwrap_or((src.start, None));
             let mut cell = scell.clone().unwrap_or_default();
             match mode {
                 FillMode::Formats => {
@@ -96,7 +101,10 @@ pub fn fill(cx: &mut Ctx, sheet: usize, src: RangeRef, target: RangeRef, mode: F
                             cell.formula = Some(Arc::new(Formula::from_expr(shifted)));
                             cell.value = Value::Empty;
                         }
-                    } else if let Some(v) = pattern.value(step, forward, src_cells.len()) {
+                    } else if let Some(v) = match per_cell.get(src_i) {
+                        Some(p) => p.value(k as i64 / src_cells.len() as i64 + 1, forward, 1),
+                        None => pattern.value(step, forward, src_cells.len()),
+                    } {
                         cell.value = v;
                     }
                     cell.style = style;
@@ -173,8 +181,14 @@ impl Pattern {
             let last = nums.last().copied().unwrap_or(0.0);
             let is_date = fmt.contains('d') || fmt.contains('y') || (fmt.contains('m') && !fmt.contains('h'));
             if nums.len() == 1 {
-                // A single number copies; a single date increments by a day.
-                return if is_date { Pattern::Linear { last, first, step: 1.0 } } else { Pattern::Copy };
+                // A single number copies; a single date increments by a day, a single time by an hour.
+                return if is_date {
+                    Pattern::Linear { last, first, step: 1.0 }
+                } else if NumberFormat::parse(fmt).kind() == FormatKind::Time {
+                    Pattern::Linear { last, first, step: 1.0 / 24.0 }
+                } else {
+                    Pattern::Copy
+                };
             }
             // Dates that differ by whole months.
             if is_date && nums.len() >= 2 {
@@ -260,8 +274,12 @@ impl Pattern {
             Pattern::TextNum { prefix, suffix, last, first, step, width } => {
                 let base = if forward { *last } else { *first };
                 let n = base + step * k * sign;
-                let n = n.abs();
-                Some(Value::text(format!("{prefix}{n:0width$}{suffix}", width = *width)))
+                // `Qtr3`, `Quarter 3` wrap after 4 like `Q3`.
+                let quarter = suffix.is_empty()
+                    && (1..=4).contains(&base)
+                    && ["q", "qtr", "quarter"].contains(&prefix.trim_end().to_ascii_lowercase().as_str());
+                let n = if quarter { (n - 1).rem_euclid(4) + 1 } else { n.abs() };
+                Some(Value::text(format!("{prefix}{n:0width$}{}", ordinal_suffix(n, suffix), width = *width)))
             }
             Pattern::List { list, last, first, step, upper, lower } => {
                 let len = list.len() as i64;
@@ -309,6 +327,23 @@ fn round15(x: f64) -> f64 {
     if !p.is_finite() || p == 0.0 { x } else { (x * p).round() / p }
 }
 
+/// `1st Period` → `2nd Period`: an English ordinal ending is rewritten to suit the new number.
+fn ordinal_suffix(n: i64, suffix: &str) -> String {
+    let (Some(end), Some(rest)) = (suffix.get(..2), suffix.get(2..)) else { return suffix.to_string() };
+    if !["st", "nd", "rd", "th"].contains(&end.to_ascii_lowercase().as_str()) || rest.starts_with(char::is_alphanumeric) {
+        return suffix.to_string();
+    }
+    let new = match (n % 10, n % 100) {
+        (_, 11..=13) => "th",
+        (1, _) => "st",
+        (2, _) => "nd",
+        (3, _) => "rd",
+        _ => "th",
+    };
+    let new = if end.chars().all(|c| c.is_ascii_uppercase()) { new.to_ascii_uppercase() } else { new.to_string() };
+    format!("{new}{rest}")
+}
+
 /// `Item 007` → ("Item ", 7, "", 3); `3rd` style leading numbers → ("", 3, "rd", 1).
 fn split_num(t: &str) -> Option<(String, i64, String, usize)> {
     let chars: Vec<char> = t.chars().collect();
@@ -338,6 +373,7 @@ pub fn series(cx: &mut Ctx, sheet: usize, r: RangeRef, rows: bool, kind: &str, s
         let style = sh.style_id(first_cell);
         let mut v = start;
         for i in 1..len {
+            let prev = v;
             v = match kind {
                 "growth" => v * step,
                 "date" => {
@@ -350,7 +386,10 @@ pub fn series(cx: &mut Ctx, sheet: usize, r: RangeRef, rows: bool, kind: &str, s
                             let mut left = step.abs() as i64;
                             while left > 0 {
                                 n += step.signum();
-                                if datetime_from_serial(sys, n).is_some_and(|d| d.weekday != 0 && d.weekday != 6) {
+                                let Some(day) = datetime_from_serial(sys, n) else {
+                                    return Err(crate::EngineError::Other("The weekday series runs past the supported date range.".into()));
+                                };
+                                if day.weekday != 0 && day.weekday != 6 {
                                     left -= 1;
                                 }
                             }
@@ -361,8 +400,9 @@ pub fn series(cx: &mut Ctx, sheet: usize, r: RangeRef, rows: bool, kind: &str, s
                 }
                 _ => v + step,
             };
+            // The stop value bounds the series in the direction it runs (a growth by 0.5 falls).
             if let Some(s) = stop
-                && ((step >= 0.0 && v > s) || (step < 0.0 && v < s))
+                && ((v >= prev && v > s) || (v < prev && v < s))
             {
                 break;
             }
@@ -579,4 +619,37 @@ mod tests {
         assert_eq!(split_num("Q003x"), Some(("Q".into(), 3, "x".into(), 3)));
         assert_eq!(split_num("abc"), None);
     }
+
+    #[test]
+    fn times_quarters_ordinals_and_mixed_sources() {
+        let mut s = crate::Session::new();
+        s.new_workbook();
+        let mut fill = |values: serde_json::Value, source: &str, target: &str| {
+            s.execute("range.setValues", serde_json::json!({"range": source.get(..2).unwrap(), "values": values})).unwrap();
+            s.execute("edit.autoFill", serde_json::json!({"source": source, "target": target})).unwrap();
+            let sh = s.doc().unwrap().wb.active().unwrap();
+            let r = RangeRef::parse(target).unwrap();
+            r.iter().map(|c| crate::display::cell_text(&s.doc().unwrap().wb, sh, c)).collect::<Vec<_>>()
+        };
+        assert_eq!(fill(serde_json::json!([["9:00"]]), "A1", "A1:A3"), ["9:00", "10:00", "11:00"]);
+        assert_eq!(fill(serde_json::json!([["Qtr3"]]), "B1", "B1:B3"), ["Qtr3", "Qtr4", "Qtr1"]);
+        assert_eq!(fill(serde_json::json!([["Quarter 4"]]), "C1", "C1:C2"), ["Quarter 4", "Quarter 1"]);
+        assert_eq!(fill(serde_json::json!([["1st Period"]]), "D1", "D1:D4"), ["1st Period", "2nd Period", "3rd Period", "4th Period"]);
+        assert_eq!(
+            fill(serde_json::json!([["Product 1"], ["On backorder"]]), "E1:E2", "E1:E6"),
+            ["Product 1", "On backorder", "Product 2", "On backorder", "Product 3", "On backorder"]
+        );
+    }
+
+    #[test]
+    fn falling_growth_series_stops_at_its_stop_value() {
+        let mut s = crate::Session::new();
+        s.new_workbook();
+        s.execute("cell.set", serde_json::json!({"cell": "A1", "input": "5"})).unwrap();
+        s.execute("edit.fillSeries", serde_json::json!({"range": "A1:A6", "type": "growth", "step": 0.5, "stop": 1})).unwrap();
+        let d = s.doc().unwrap();
+        let sh = d.wb.active().unwrap();
+        let growth: Vec<String> = (1..6).map(|r| crate::display::cell_text(&d.wb, sh, CellRef::new(r, 0))).collect();
+        assert_eq!(growth, ["2.5", "1.25", "", "", ""]);
+    }
 }

crates/engine/src/io.rs

@@ -102,6 +102,8 @@ fn open_plain(name: &str, bytes: &[u8]) -> Result<(Workbook, Vec<String>)> {
     let import = match sniffed {
         gridcraft_xlsx::Format::Ods => Some(FileKind::Ods),
         gridcraft_xlsx::Format::Xlsb => Some(FileKind::Xlsb),
+        // An XLSX package is never read as ODS/XLSB just because of its name.
+        gridcraft_xlsx::Format::Xlsx => None,
         _ => kind.filter(|k| matches!(k, FileKind::Ods | FileKind::Xlsb)),
     };
     if let Some(import) = import {
@@ -109,7 +111,8 @@ fn open_plain(name: &str, bytes: &[u8]) -> Result<(Workbook, Vec<String>)> {
         let (wb, report) = read(bytes).map_err(|e| EngineError::Other(format!("We can't import '{name}': {e}")))?;
         return Ok((wb, report.warnings));
     }
-    if sniffed == gridcraft_xlsx::Format::Xlsx || kind == Some(FileKind::Xlsx) {
+    // Text named `.xlsx` is read as text.
+    if sniffed == gridcraft_xlsx::Format::Xlsx || (kind == Some(FileKind::Xlsx) && sniffed != gridcraft_xlsx::Format::Csv) {
         let (wb, report) = gridcraft_xlsx::read_xlsx(bytes).map_err(|e| EngineError::Other(format!("We can't open '{name}': {e}")))?;
         return Ok((wb, report.warnings));
     }
@@ -153,8 +156,19 @@ fn rename_first_sheet(wb: &mut Workbook, path: &str) {
 
 /// Encodes a workbook in the format chosen by `path`'s extension.
 pub fn save_bytes(wb: &Workbook, path: &str) -> Result<Vec<u8>> {
+    // An unknown or missing extension is refused rather than written as an XLSX under that name:
+    // a typo like `.cvs` would otherwise produce a file no other app recognises.
+    let Some(kind) = FileKind::from_path(path) else {
+        let name = std::path::Path::new(path).file_name().and_then(|n| n.to_str()).unwrap_or(path);
+        return Err(EngineError::Other(format!("{name}: unknown file format. Save as .xlsx, .csv, .tsv, .json or .html.")));
+    };
+    save_bytes_as(wb, path, kind)
+}
+
+/// Encodes a workbook as `kind`, whatever `path`'s extension says.
+pub fn save_bytes_as(wb: &Workbook, path: &str, kind: FileKind) -> Result<Vec<u8>> {
     let sheet = wb.active_sheet;
-    match FileKind::from_path(path).unwrap_or(FileKind::Xlsx) {
+    match kind {
         // The extension picks the package kind; only the macro-enabled kinds (.xlsm, .xltm) carry
         // the VBA project, so any other name saves without it, as Excel does.
         FileKind::Xlsx => gridcraft_xlsx::write_xlsx_as(wb, gridcraft_xlsx::XlsxKind::from_path(path)).map_err(|e| EngineError::Other(e.to_string())),
@@ -167,7 +181,7 @@ pub fn save_bytes(wb: &Workbook, path: &str) -> Result<Vec<u8>> {
         FileKind::Csv => wb.sheet(sheet).map(|sh| csv(wb, sh, wb.csv_delimiter.unwrap_or(b','))).transpose().map(Option::unwrap_or_default),
         FileKind::Tsv => wb.sheet(sheet).map(|sh| csv(wb, sh, b'\t')).transpose().map(Option::unwrap_or_default),
         FileKind::Json => serde_json::to_vec_pretty(wb).map_err(|e| EngineError::Other(e.to_string())),
-        FileKind::Html => Ok(to_html(wb, sheet).into_bytes()),
+        FileKind::Html => to_html(wb, sheet).map(String::into_bytes),
     }
 }
 
@@ -297,9 +311,12 @@ impl std::fmt::Write for ClipboardHtml {
     }
 }
 
+/// Most rows Save as Web Page writes. A sheet whose used range is taller fails instead of losing cells.
+const HTML_EXPORT_MAX_ROWS: u32 = 100_001;
+
 /// A sheet as a standalone HTML table (Save as Web Page).
-pub fn to_html(wb: &Workbook, sheet: usize) -> String {
-    let Some(sh) = wb.sheet(sheet) else { return String::new() };
+pub fn to_html(wb: &Workbook, sheet: usize) -> Result<String> {
+    let Some(sh) = wb.sheet(sheet) else { return Ok(String::new()) };
     let mut out = String::new();
     let _ = write!(
         out,
@@ -307,7 +324,13 @@ pub fn to_html(wb: &Workbook, sheet: usize) -> String {
         esc(&sh.name)
     );
     if let Some(r) = sh.used_range() {
-        for row in r.start.row..=r.end.row.min(r.start.row + 100_000) {
+        if r.height() > HTML_EXPORT_MAX_ROWS {
+            return Err(EngineError::Other(format!(
+                "the sheet is too tall for a web page ({} rows, at most {HTML_EXPORT_MAX_ROWS}). Save as .xlsx or CSV instead.",
+                r.height()
+            )));
+        }
+        for row in r.start.row..=r.end.row {
             if sh.is_row_hidden(row) {
                 continue;
             }
@@ -330,7 +353,7 @@ pub fn to_html(wb: &Workbook, sheet: usize) -> String {
         }
     }
     out.push_str("</table></body></html>");
-    out
+    Ok(out)
 }
 
 #[cfg(not(target_arch = "wasm32"))]
@@ -351,8 +374,12 @@ pub fn read_file(path: &str) -> Result<Vec<u8>> {
 pub fn write_file(path: &str, bytes: &[u8]) -> Result<()> {
     // Write to a temporary file, then rename: a crash never leaves a half-written workbook.
     let tmp = format!("{path}.sctmp");
-    std::fs::write(&tmp, bytes).map_err(|e| EngineError::Other(format!("{path}: {e}")))?;
-    std::fs::rename(&tmp, path).map_err(|e| EngineError::Other(format!("{path}: {e}")))
+    std::fs::write(&tmp, bytes).and_then(|()| std::fs::rename(&tmp, path)).map_err(|e| {
+        // A write or rename that fails (full disk, the workbook locked by another app) leaves
+        // no temporary file beside the user's workbook.
+        let _ = std::fs::remove_file(&tmp);
+        EngineError::Other(format!("{path}: {e}"))
+    })
 }
 
 #[cfg(target_arch = "wasm32")]
@@ -430,6 +457,20 @@ pub fn image_size(data: &[u8]) -> Option<(u32, u32)> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn html_export_fails_instead_of_dropping_cells_past_the_row_limit() {
+        let mut wb = Workbook::new();
+        let sh = wb.sheet_mut(0).unwrap();
+        sh.set_value(CellRef::new(0, 0), gridcraft_core::Value::text("near"));
+        sh.set_value(CellRef::new(149_999, 0), gridcraft_core::Value::text("far"));
+        assert!(save_bytes(&wb, "book.html").is_err());
+        let sh = wb.sheet_mut(0).unwrap();
+        sh.remove_cell(CellRef::new(149_999, 0));
+        sh.set_value(CellRef::new(100_000, 0), gridcraft_core::Value::text("far"));
+        let html = String::from_utf8(save_bytes(&wb, "book.html").unwrap()).unwrap();
+        assert!(html.contains(">near</td>") && html.contains(">far</td>"));
+    }
+
     #[test]
     fn macros_are_saved_only_into_xlsm() {
         let mut wb = Workbook::new();
@@ -446,6 +487,26 @@ mod tests {
         assert!(wb.vba_project.is_some(), "the open workbook keeps its macros");
     }
 
+    /// A save that can't be put in place (here a folder already has the workbook's name, as
+    /// with a file another app holds locked) fails without leaving `<name>.sctmp` behind.
+    #[cfg(not(target_arch = "wasm32"))]
+    #[test]
+    fn failed_save_leaves_no_temporary_file() {
+        let dir = std::env::temp_dir().join(format!("gridcraft-write-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        let blocked = dir.join("Book1.xlsx");
+        std::fs::create_dir(&blocked).unwrap();
+        assert!(write_file(blocked.to_str().unwrap(), b"workbook").is_err());
+        assert!(!dir.join("Book1.xlsx.sctmp").exists(), "the temporary file is removed");
+        // An ordinary save still works and leaves only the workbook.
+        let ok = dir.join("Book2.xlsx");
+        write_file(ok.to_str().unwrap(), b"workbook").unwrap();
+        assert_eq!(std::fs::read(&ok).unwrap(), b"workbook");
+        assert!(!dir.join("Book2.xlsx.sctmp").exists());
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
     /// A minimal compound (CFB/OLE2) file — FAT in sector 0, directory in sector 1 — holding a
     /// root entry and the given stream names.
     fn cfb(streams: &[&str]) -> Vec<u8> {
@@ -609,4 +670,19 @@ mod tests {
             "{types}"
         );
     }
+
+    #[test]
+    fn content_wins_over_a_mismatched_extension() {
+        let mut wb = Workbook::new();
+        wb.sheet_mut(0).unwrap().set_value(CellRef::new(0, 0), gridcraft_core::Value::Number(7.0));
+        let package = save_bytes(&wb, "book.xlsx").unwrap();
+        for name in ["book.xlsx", "book.ods", "book.xlsb", "book.csv"] {
+            let (opened, _) = open_bytes(name, &package).unwrap_or_else(|e| panic!("{name}: {e}"));
+            assert_eq!(opened.sheet(0).unwrap().value(CellRef::new(0, 0)), gridcraft_core::Value::Number(7.0), "{name}");
+        }
+        for name in ["data.xlsx", "data.csv"] {
+            let (opened, _) = open_bytes(name, b"a,b\n1,2\n").unwrap_or_else(|e| panic!("{name}: {e}"));
+            assert_eq!(opened.sheet(0).unwrap().value(CellRef::new(0, 1)), gridcraft_core::Value::text("b"), "{name}");
+        }
+    }
 }

crates/engine/src/lib.rs

@@ -108,6 +108,9 @@ pub struct DocState {
     pub sheet_selections: Vec<Selection>,
     /// Allow Edit Ranges unlocked with their password in this session: (sheet name, title).
     pub unlocked_ranges: Vec<(String, String)>,
+    /// The format `path`'s content was recognised as when its extension doesn't name one (an
+    /// XLSX called `budget.dat`): Save writes it back in that format.
+    pub content_kind: Option<io::FileKind>,
 }
 
 static NEXT_UID: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(1);
@@ -132,6 +135,7 @@ impl DocState {
             title,
             sheet_selections: vec![],
             unlocked_ranges: vec![],
+            content_kind: None,
         }
     }
     pub fn is_dirty(&self) -> bool {

crates/engine/src/pivot.rs

@@ -560,6 +560,8 @@ struct Line {
     values: bool,
     /// (column, value, indent, number format)
     labels: Vec<(usize, Value, u8, Option<String>)>,
+    /// The value field of the line when Σ Values sits in Rows (`None`: one per data column).
+    vi: Option<usize>,
 }
 
 #[derive(Clone, Copy, PartialEq, Eq)]
@@ -579,6 +581,10 @@ struct Ctx<'a> {
     rows: Vec<&'a PivotField>,
     row_items: Vec<FieldItems>,
     row_fmts: Vec<String>,
+    /// Depth of Σ Values among the row fields when it sits in Rows (two or more value fields).
+    vpos: Option<usize>,
+    /// Value field captions.
+    val_names: Vec<String>,
 }
 
 impl Ctx<'_> {
@@ -588,26 +594,105 @@ impl Ctx<'_> {
         (it.value.clone(), fmt, it.label.clone())
     }
 
-    fn flatten(&self, nodes: &[Node], depth: usize, prefix: &mut Vec<u32>, out: &mut Vec<Line>) {
+    /// (column, indent) of a row level (Σ Values counts as a level) in Compact/Outline form.
+    fn level_cell(&self, level: usize) -> (usize, u8) {
+        if self.pt.layout == PivotLayout::Outline { (level, 0) } else { (0, level.min(250) as u8) }
+    }
+
+    /// Σ Values comes right here, at row field depth `depth` (`vi`: the value field already chosen above).
+    fn values_here(&self, depth: usize, vi: Option<usize>) -> bool {
+        vi.is_none() && self.vpos == Some(depth)
+    }
+
+    /// Per-value subtotal lines of an item with Σ Values below it ("East Sum of Sales").
+    fn value_subtotals(&self, col: usize, indent: u8, label: &str, prefix: &[u32], out: &mut Vec<Line>) {
+        for (vi, name) in self.val_names.iter().enumerate() {
+            out.push(Line {
+                kind: LineKind::Subtotal,
+                leaf: false,
+                path: prefix.to_vec(),
+                values: true,
+                labels: vec![(col, Value::text(format!("{label} {name}")), indent, None)],
+                vi: Some(vi),
+            });
+        }
+    }
+
+    /// The Σ Values level at row field depth `depth`: one item per value field, each followed by
+    /// the row fields below it (`nodes`) or, innermost, holding that value.
+    fn flatten_values(&self, nodes: &[Node], depth: usize, prefix: &mut Vec<u32>, out: &mut Vec<Line>) {
+        let (col, indent) = self.level_cell(depth);
+        for (vi, name) in self.val_names.iter().enumerate() {
+            let labels = vec![(col, Value::text(name.as_str()), indent, None)];
+            let leaf = nodes.is_empty();
+            out.push(Line { kind: LineKind::Item(!leaf), leaf, path: prefix.clone(), values: leaf, labels, vi: Some(vi) });
+            if !leaf {
+                self.flatten(nodes, depth, Some(vi), prefix, out);
+            }
+        }
+    }
+
+    fn flatten(&self, nodes: &[Node], depth: usize, vi: Option<usize>, prefix: &mut Vec<u32>, out: &mut Vec<Line>) {
+        if self.values_here(depth, vi) {
+            self.flatten_values(nodes, depth, prefix, out);
+            return;
+        }
         let n = self.rows.len();
-        let outline = self.pt.layout == PivotLayout::Outline;
+        // Σ Values still to come below this level: totals need one line per value field.
+        let values_below = vi.is_none() && self.vpos.is_some();
+        let (col, indent) = self.level_cell(depth + usize::from(vi.is_some() && self.vpos.is_some()));
         for node in nodes {
             prefix.push(node.item);
             let (v, fmt, label) = self.label_cell(depth, node.item);
-            let (col, indent) = if outline { (depth, 0) } else { (0, depth.min(250) as u8) };
             let collapsed = depth + 1 < n && self.rows.get(depth).is_some_and(|f| is_collapsed(f, &label));
-            if depth + 1 >= n || collapsed || node.children.is_empty() {
+            let leaf = depth + 1 >= n || collapsed || node.children.is_empty();
+            if leaf && !values_below {
                 out.push(Line {
                     kind: LineKind::Item(depth + 1 < n),
                     leaf: true,
                     path: prefix.clone(),
                     values: true,
                     labels: vec![(col, v, indent, fmt)],
+                    vi,
                 });
+            } else if leaf {
+                out.push(Line {
+                    kind: LineKind::Item(true),
+                    leaf: false,
+                    path: prefix.clone(),
+                    values: false,
+                    labels: vec![(col, v, indent, fmt)],
+                    vi,
+                });
+                // Outline gives each level its own column, so the captions go in the Values
+                // column even when the levels between are collapsed away.
+                let level = if self.pt.layout == PivotLayout::Outline { self.vpos.unwrap_or(depth + 1) } else { depth + 1 };
+                self.flatten_values(&[], level, prefix, out);
+            } else if values_below {
+                // Subtotals per value field, below the group (one line can't hold them all).
+                out.push(Line {
+                    kind: LineKind::Item(true),
+                    leaf: false,
+                    path: prefix.clone(),
+                    values: false,
+                    labels: vec![(col, v, indent, fmt)],
+                    vi,
+                });
+                self.flatten(&node.children, depth + 1, None, prefix, out);
+                if self.pt.subtotals {
+                    self.value_subtotals(col, indent, &label, prefix, out);
+                }
             } else {
                 let top = self.pt.subtotals && self.pt.subtotals_top;
-                out.push(Line { kind: LineKind::Item(true), leaf: false, path: prefix.clone(), values: top, labels: vec![(col, v, indent, fmt)] });
-                self.flatten(&node.children, depth + 1, prefix, out);
+                out.push(Line {
+                    kind: LineKind::Item(true),
+                    leaf: false,
+                    path: prefix.clone(),
+                    values: top,
+                    labels: vec![(col, v, indent, fmt)],
+                    vi,
+                });
+                self.flatten(&node.children, depth + 1, vi, prefix, out);
                 if self.pt.subtotals && !self.pt.subtotals_top {
                     out.push(Line {
                         kind: LineKind::Subtotal,
@@ -615,6 +700,7 @@ impl Ctx<'_> {
                         path: prefix.clone(),
                         values: true,
                         labels: vec![(col, Value::text(format!("{label} Total")), indent, None)],
+                        vi,
                     });
                 }
             }
@@ -622,7 +708,8 @@ impl Ctx<'_> {
         }
     }
 
-    fn flatten_tabular(
+    /// Tabular form of [`Self::flatten_values`]: the first line also carries the parents' labels.
+    fn flatten_tabular_values(
         &self,
         nodes: &[Node],
         depth: usize,
@@ -630,24 +717,57 @@ impl Ctx<'_> {
         pending: &[(usize, Value, u8, Option<String>)],
         out: &mut Vec<Line>,
     ) {
+        for (vi, name) in self.val_names.iter().enumerate() {
+            let mut labels: Vec<(usize, Value, u8, Option<String>)> = if vi == 0 { pending.to_vec() } else { vec![] };
+            labels.push((depth, Value::text(name.as_str()), 0, None));
+            if nodes.is_empty() {
+                out.push(Line { kind: LineKind::Item(false), leaf: true, path: prefix.clone(), values: true, labels, vi: Some(vi) });
+            } else {
+                self.flatten_tabular(nodes, depth, Some(vi), prefix, &labels, out);
+            }
+        }
+    }
+
+    fn flatten_tabular(
+        &self,
+        nodes: &[Node],
+        depth: usize,
+        vi: Option<usize>,
+        prefix: &mut Vec<u32>,
+        pending: &[(usize, Value, u8, Option<String>)],
+        out: &mut Vec<Line>,
+    ) {
+        if self.values_here(depth, vi) {
+            self.flatten_tabular_values(nodes, depth, prefix, pending, out);
+            return;
+        }
         let n = self.rows.len();
+        let values_below = vi.is_none() && self.vpos.is_some();
+        let col = depth + usize::from(vi.is_some() && self.vpos.is_some());
         for (i, node) in nodes.iter().enumerate() {
             prefix.push(node.item);
             let (v, fmt, label) = self.label_cell(depth, node.item);
             let mut labels: Vec<(usize, Value, u8, Option<String>)> = if i == 0 { pending.to_vec() } else { vec![] };
-            labels.push((depth, v, 0, fmt));
+            labels.push((col, v, 0, fmt));
             let collapsed = depth + 1 < n && self.rows.get(depth).is_some_and(|f| is_collapsed(f, &label));
             if depth + 1 >= n || collapsed || node.children.is_empty() {
-                out.push(Line { kind: LineKind::Item(false), leaf: true, path: prefix.clone(), values: true, labels });
+                if values_below {
+                    self.flatten_tabular_values(&[], self.vpos.unwrap_or(depth + 1), prefix, &labels, out);
+                } else {
+                    out.push(Line { kind: LineKind::Item(false), leaf: true, path: prefix.clone(), values: true, labels, vi });
+                }
             } else {
-                self.flatten_tabular(&node.children, depth + 1, prefix, &labels, out);
-                if self.pt.subtotals {
+                self.flatten_tabular(&node.children, depth + 1, vi, prefix, &labels, out);
+                if self.pt.subtotals && values_below {
+                    self.value_subtotals(col, 0, &label, prefix, out);
+                } else if self.pt.subtotals {
                     out.push(Line {
                         kind: LineKind::Subtotal,
                         leaf: false,
                         path: prefix.clone(),
                         values: true,
-                        labels: vec![(depth, Value::text(format!("{label} Total")), 0, None)],
+                        labels: vec![(col, Value::text(format!("{label} Total")), 0, None)],
+                        vi,
                     });
                 }
             }
@@ -693,6 +813,12 @@ enum ValSrc {
     Calc(usize),
 }
 
+/// True when `col_groups` distinct column leaves (plus the grand-total column) times `values` value fields
+/// (at least one data column per group) already exceed the sheet width. This is a lower bound on the final column count.
+fn data_cols_exceed_sheet(col_groups: usize, grand_total: bool, values: usize) -> bool {
+    (col_groups + usize::from(grand_total)).saturating_mul(values.max(1)) > MAX_COLS as usize
+}
+
 /// Computes a PivotTable report from the workbook.
 pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Output, String> {
     let src = read_source(wb, &pt.source, pivot_sheet)?;
@@ -745,6 +871,14 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
 
     let k = vals.len();
     let empty = rows.is_empty() && cols.is_empty() && vals.is_empty();
+    // Σ Values in Rows (it exists with two or more value fields): its depth among the row fields
+    // found in the source.
+    let vpos: Option<usize> = (pt.values_on_rows && k > 1).then(|| {
+        let p = pt.values_position.unwrap_or(pt.rows.len());
+        pt.rows.iter().take(p).filter(|f| src.col(&f.source_col).is_some()).count()
+    });
+    let on_rows = vpos.is_some();
+    let row_levels = rows.len() + usize::from(on_rows);
 
     // ---- aggregate
     let mut row_items: Vec<FieldItems> = rows.iter().map(|_| FieldItems::default()).collect();
@@ -752,6 +886,7 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
     let mut aggs: AggMap = HashMap::new();
     let mut row_set: HashSet<Vec<u32>> = HashSet::new();
     let mut col_set: HashSet<Vec<u32>> = HashSet::new();
+    let mut col_leaves: HashSet<Vec<u32>> = HashSet::new();
     let filter_fmts: Vec<String> = filters.iter().map(|f| fmt_of(f.0)).collect();
     let row_fmts: Vec<String> = rows.iter().map(|(c, _)| fmt_of(*c)).collect();
     let col_fmts: Vec<String> = cols.iter().map(|(c, _)| fmt_of(*c)).collect();
@@ -788,8 +923,22 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
                 }
             }
         }
+        // The column leaf this record lands in: its path cut after the first collapsed item (as in `flatten_cols`).
+        let shown = cols
+            .iter()
+            .zip(col_items.iter())
+            .zip(cp.iter())
+            .position(|(((_, f), fi), &it)| !f.collapsed_items.is_empty() && is_collapsed(f, &fi.label(it)))
+            .map_or(cp.len(), |d| d + 1);
+        if !col_leaves.contains(&cp[..shown]) {
+            col_leaves.insert(cp[..shown].to_vec());
+        }
         row_set.insert(rp);
         col_set.insert(cp);
+        // Refuse a report that cannot fit before the accumulators for more column groups are allocated.
+        if !cols.is_empty() && data_cols_exceed_sheet(col_leaves.len(), pt.grand_totals_rows, k) {
+            return Err("The PivotTable report will not fit on the sheet.".into());
+        }
         if aggs.len() > 5_000_000 {
             return Err("The PivotTable report is too large.".into());
         }
@@ -806,24 +955,32 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
     collect_siblings(&row_tree, &mut Vec::new(), &mut siblings);
     let level0: Vec<u32> = row_tree.iter().map(|n| n.item).collect();
 
-    let ctx = Ctx { pt, rows: row_fields.clone(), row_items, row_fmts: row_fmts.clone() };
+    let val_names: Vec<String> = vals.iter().map(|(_, v)| v.name.clone()).collect();
+    let ctx = Ctx { pt, rows: row_fields.clone(), row_items, row_fmts: row_fmts.clone(), vpos, val_names: val_names.clone() };
     let mut lines: Vec<Line> = Vec::new();
-    if rows.is_empty() {
-        lines.push(Line { kind: LineKind::Item(false), leaf: true, path: vec![], values: true, labels: vec![] });
+    if row_levels == 0 {
+        lines.push(Line { kind: LineKind::Item(false), leaf: true, path: vec![], values: true, labels: vec![], vi: None });
     } else {
         if pt.layout == PivotLayout::Tabular {
-            ctx.flatten_tabular(&row_tree, 0, &mut Vec::new(), &[], &mut lines);
+            ctx.flatten_tabular(&row_tree, 0, None, &mut Vec::new(), &[], &mut lines);
         } else {
-            ctx.flatten(&row_tree, 0, &mut Vec::new(), &mut lines);
+            ctx.flatten(&row_tree, 0, None, &mut Vec::new(), &mut lines);
         }
-        if pt.grand_totals_cols {
-            lines.push(Line {
+        // With only Σ Values in Rows its items are the totals already.
+        if pt.grand_totals_cols && !rows.is_empty() {
+            let grand = |text: String, vi: Option<usize>| Line {
                 kind: LineKind::Grand,
                 leaf: false,
                 path: vec![],
                 values: true,
-                labels: vec![(0, Value::text("Grand Total"), 0, None)],
-            });
+                labels: vec![(0, Value::text(text), 0, None)],
+                vi,
+            };
+            if on_rows {
+                lines.extend(val_names.iter().enumerate().map(|(vi, name)| grand(format!("Total {name}"), Some(vi))));
+            } else {
+                lines.push(grand("Grand Total".into(), None));
+            }
         }
     }
     let mut specs: Vec<ColSpec> = Vec::new();
@@ -837,7 +994,10 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
     }
     let mut data_cols: Vec<(usize, Option<usize>)> = Vec::new();
     for (si, _) in specs.iter().enumerate() {
-        if k == 0 {
+        if on_rows {
+            // Each line names its value field; one data column per column item.
+            data_cols.push((si, None));
+        } else if k == 0 {
             if !cols.is_empty() {
                 data_cols.push((si, None));
             }
@@ -852,12 +1012,12 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
     }
 
     let compact = pt.layout == PivotLayout::Compact;
-    let l = if rows.is_empty() && cols.is_empty() {
+    let l = if row_levels == 0 && cols.is_empty() {
         0
     } else if compact {
         1
     } else {
-        rows.len().max(1)
+        row_levels.max(1)
     };
     let mut width = l + data_cols.len();
     if !shown_filters.is_empty() {
@@ -903,14 +1063,19 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
     let val_name = |vi: usize| vals.get(vi).map(|(_, v)| v.name.clone()).unwrap_or_default();
     let headers_on = pt.show_headers;
     let row_header = |g: &mut Grid, r: usize| {
-        if rows.is_empty() || !headers_on {
+        if row_levels == 0 || !headers_on {
             return;
         }
         if compact {
             g.set(r, 0, Value::text("Row Labels"), CellKind::Header, 0, None);
         } else {
-            for (i, f) in row_fields.iter().enumerate() {
-                g.set(r, i, Value::text(f.source_col.as_str()), CellKind::Header, 0, None);
+            // One column per row field, Σ Values ("Values") at its place.
+            let mut names: Vec<&str> = row_fields.iter().map(|f| f.source_col.as_str()).collect();
+            if let Some(p) = vpos {
+                names.insert(p.min(names.len()), "Values");
+            }
+            for (i, name) in names.into_iter().enumerate() {
+                g.set(r, i, Value::text(name), CellKind::Header, 0, None);
             }
         }
     };
@@ -920,8 +1085,11 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
         let r = g.push_row(RowKind::Header)?;
         row_header(&mut g, r);
         for (j, (_, vi)) in data_cols.iter().enumerate() {
-            if let Some(vi) = vi {
-                g.set(r, l + j, Value::text(val_name(*vi)), CellKind::Header, 0, None);
+            match vi {
+                Some(vi) => g.set(r, l + j, Value::text(val_name(*vi)), CellKind::Header, 0, None),
+                // Values on rows, no column field: the one data column is the grand total.
+                None if on_rows => g.set(r, l + j, Value::text("Total"), CellKind::Header, 0, None),
+                None => {}
             }
         }
     } else {
@@ -933,7 +1101,7 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
             let caption = if compact { "Column Labels".to_string() } else { col_fields.first().map(|f| f.source_col.clone()).unwrap_or_default() };
             g.set(cap, l, Value::text(caption), CellKind::Header, 0, None);
         }
-        let levels = cols.len() + usize::from(k > 1);
+        let levels = cols.len() + usize::from(k > 1 && !on_rows);
         let first_level = g.rows.len();
         for _ in 0..levels {
             g.push_row(RowKind::Header)?;
@@ -1048,17 +1216,19 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
                 && (k > 1 || parts.is_empty())
             {
                 parts.push(val_name(*vi));
+            } else if parts.is_empty() {
+                parts.push("Total".into());
             }
             Some(((l + j) as u32, parts.join(" - ")))
         })
         .filter(|_| k > 0)
         .collect();
-    let label_col = if rows.is_empty() {
+    let label_col = if row_levels == 0 {
         None
     } else if compact {
         Some(0)
     } else {
-        Some(rows.len().saturating_sub(1) as u32)
+        Some(row_levels.saturating_sub(1) as u32)
     };
     for line in &lines {
         let rk = match line.kind {
@@ -1082,8 +1252,9 @@ pub fn compute(wb: &Workbook, pt: &PivotTable, pivot_sheet: usize) -> Result<Out
             continue;
         }
         let rp = line.path.as_slice();
-        for (j, (si, vi)) in data_cols.iter().enumerate() {
-            let (Some(spec), Some(vi)) = (specs.get(*si), vi) else { continue };
+        for (j, (si, col_vi)) in data_cols.iter().enumerate() {
+            let line_vi = col_vi.or(line.vi);
+            let (Some(spec), Some(vi)) = (specs.get(*si), &line_vi) else { continue };
             let Some((_, vdef)) = vals.get(*vi) else { continue };
             let cp = spec.path.as_slice();
             let Some(raw) = get(rp, cp, *vi) else { continue };
@@ -1428,3 +1599,17 @@ pub fn clear_output(wb: &mut Workbook, sheet: usize, idx: usize) {
         p.last_range = None;
     }
 }
+
+#[cfg(test)]
+mod fit_tests {
+    use super::data_cols_exceed_sheet;
+
+    #[test]
+    fn column_budget_counts_value_fields_and_grand_total() {
+        assert!(!data_cols_exceed_sheet(64, true, 128));
+        assert!(data_cols_exceed_sheet(64, true, 256));
+        assert!(!data_cols_exceed_sheet(64, false, 256));
+        assert!(!data_cols_exceed_sheet(16_384, false, 0));
+        assert!(data_cols_exceed_sheet(16_385, false, 0));
+    }
+}

crates/engine/src/selection.rs

@@ -43,6 +43,13 @@ impl Selection {
     pub fn is_single_cell(&self) -> bool {
         self.ranges.len() == 1 && self.current().is_single()
     }
+    /// The corner of the current area opposite the anchor: the end that Shift+arrows move.
+    pub fn moving_end(&self) -> CellRef {
+        let r = self.current();
+        let row = if self.anchor.row == r.start.row { r.end.row } else { r.start.row };
+        let col = if self.anchor.col == r.start.col { r.end.col } else { r.start.col };
+        CellRef::new(row, col)
+    }
     /// Extends the current area from the anchor to `to` (Shift+click / Shift+arrows).
     pub fn extend_to(&mut self, to: CellRef) {
         let r = RangeRef::new(self.anchor, to);

crates/engine/src/tests.rs

@@ -805,6 +805,46 @@ fn sort_and_filter() {
     assert_eq!(r["hiddenRows"], 1);
 }
 
+/// Top 10 keeps the top or bottom N items or percent, ties at the threshold included.
+#[test]
+fn filter_top10_items_and_percent() {
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["Score"], [5], [1], [9], [3], [9], [7], ["x"]]})).unwrap();
+    s.execute("selection.set", json!({"cell": "A1"})).unwrap();
+    s.execute("data.filter", json!({})).unwrap();
+    // Top 2 items: 9, 9 (the "x" text row is hidden too).
+    let r = s.execute("data.filterBy", json!({"column": "A", "top": {"count": 2}})).unwrap();
+    assert_eq!(r["hiddenRows"], 5);
+    // Bottom 2 items: 1, 3.
+    let r = s.execute("data.filterBy", json!({"column": "A", "top": {"count": 2, "bottom": true}})).unwrap();
+    assert_eq!(r["hiddenRows"], 5);
+    // Top 50 percent of 6 numbers = 3 items; the threshold 7 keeps 9, 9, 7.
+    let r = s.execute("data.filterBy", json!({"column": "A", "top": {"count": 50, "percent": true}})).unwrap();
+    assert_eq!(r["hiddenRows"], 4);
+}
+
+/// Two Top 10 criteria on one column (possible in a native JSON file) each keep their own
+/// cutoff: Top 3 and Bottom 4 of 1..5 keep 3 and 4.
+#[test]
+fn filter_top10_two_criteria_on_one_column() {
+    use gridcraft_model::FilterCriterion;
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["N"], [1], [2], [3], [4], [5]]})).unwrap();
+    s.execute("selection.set", json!({"cell": "A1"})).unwrap();
+    s.execute("data.filter", json!({})).unwrap();
+    let sh = std::sync::Arc::make_mut(&mut s.doc_mut().unwrap().wb).sheet_mut(0).unwrap();
+    if let Some(af) = sh.autofilter.as_mut() {
+        af.criteria = vec![
+            (0, FilterCriterion::Top10 { bottom: false, percent: false, count: 3 }),
+            (0, FilterCriterion::Top10 { bottom: true, percent: false, count: 4 }),
+        ];
+    }
+    s.execute("data.reapply", json!({})).unwrap();
+    let hidden: Vec<u32> = s.active().unwrap().wb.sheet(0).unwrap().rows.iter().filter(|(_, r)| r.hidden).map(|(k, _)| *k).collect();
+    // Rows are 0-based: values 1, 2 and 5 sit on rows 1, 2 and 5.
+    assert_eq!(hidden, vec![1, 2, 5]);
+}
+
 /// Turning the filter on with only the header row selected filters the data below it (#201).
 #[test]
 fn filter_on_a_selected_header_row_covers_the_data_below() {
@@ -1018,6 +1058,48 @@ fn tables_and_structured_refs() {
     assert_eq!(v(&s, "B4"), Value::Number(7.0));
 }
 
+#[test]
+fn structured_refs_to_columns_with_edge_spaces() {
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["Item", "Qty "], ["a", 2], ["b", 3]]})).unwrap();
+    s.execute("insert.table", json!({"range": "A1:B3", "hasHeaders": true})).unwrap();
+    s.execute("table.totalRow", json!({"on": true, "table": "Table1"})).unwrap();
+    assert_eq!(v(&s, "B4"), Value::Number(5.0));
+    for (cell, input) in [
+        ("F1", "=SUM(Table1[Qty ])"),
+        ("F2", "=Table1[[#Totals],[Qty ]]"),
+        ("F3", "=SUBTOTAL(109,Table1[Qty ])"),
+        ("F4", "=SUM(Table1[[Qty ]])"),
+        ("F5", "=SUM(Table1[Qty])"),
+        ("C2", "=Table1[@[Qty ]]*10"),
+    ] {
+        s.execute("cell.set", json!({"cell": cell, "input": input})).unwrap();
+    }
+    let n = Value::Number;
+    assert_eq!([v(&s, "F1"), v(&s, "F2"), v(&s, "F3"), v(&s, "F4")], [n(5.0), n(5.0), n(5.0), n(5.0)]);
+    assert_eq!(v(&s, "F5"), Value::Error(gridcraft_core::CellError::Ref));
+    assert_eq!(v(&s, "C2"), n(20.0));
+    assert_eq!(s.execute("cell.get", json!({"cell": "F3"})).unwrap()["formula"], "=SUBTOTAL(109,Table1[[Qty ]])");
+
+    let r = s.execute("file.saveBytes", json!({"format": "xlsx"})).unwrap();
+    let b64 = r["base64"].as_str().unwrap().to_string();
+    s.execute("file.open", json!({"name": "x.xlsx", "base64": b64})).unwrap();
+    assert_eq!(s.execute("cell.get", json!({"cell": "F3"})).unwrap()["formula"], "=SUBTOTAL(109,Table1[[Qty ]])");
+    assert_eq!([v(&s, "F1"), v(&s, "F2"), v(&s, "F3")], [n(5.0), n(5.0), n(5.0)]);
+fn table_rename_keeps_a_defined_name_with_the_same_name() {
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["Qty"], [7]]})).unwrap();
+    s.execute("cell.set", json!({"cell": "D1", "input": "100"})).unwrap();
+    s.execute("insert.table", json!({"range": "A1:A2", "header": true, "name": "Data"})).unwrap();
+    s.execute("formulas.defineName", json!({"name": "Data", "refersTo": "=Sheet1!$D$1"})).unwrap();
+    s.execute("cell.set", json!({"cell": "E1", "input": "=Data"})).unwrap();
+    s.execute("cell.set", json!({"cell": "F1", "input": "=SUM(Data[Qty])"})).unwrap();
+    s.execute("table.rename", json!({"table": "Data", "name": "Later"})).unwrap();
+    assert_eq!(s.execute("cell.get", json!({"cell": "E1"})).unwrap()["formula"], "=Data");
+    assert_eq!(s.execute("cell.get", json!({"cell": "F1"})).unwrap()["formula"], "=SUM(Later[Qty])");
+    assert_eq!((v(&s, "E1"), v(&s, "F1")), (Value::Number(100.0), Value::Number(7.0)));
+}
+
 #[test]
 fn slicer_filters_table() {
     let mut s = s();
@@ -1170,6 +1252,22 @@ fn insert_and_delete_cells_never_shift_part_of_a_table() {
     assert!(e.to_string().contains("shift cells in a table"), "{e}");
 }
 
+#[test]
+fn table_names_with_a_hyphen_are_rejected() {
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["Qty"], [7]]})).unwrap();
+    let e = s.execute("insert.table", json!({"range": "A1:A2", "header": true, "name": "A-B"})).unwrap_err();
+    assert!(e.to_string().contains("not valid"), "{e}");
+    assert!(s.doc().unwrap().wb.table("A-B").is_none());
+    s.execute("insert.table", json!({"range": "A1:A2", "header": true, "name": "Sales"})).unwrap();
+    let e = s.execute("table.rename", json!({"table": "Sales", "name": "A-B"})).unwrap_err();
+    assert!(e.to_string().contains("not valid"), "{e}");
+    assert!(s.doc().unwrap().wb.table("Sales").is_some());
+    assert!(s.execute("table.rename", json!({"table": "Sales", "name": ".AB"})).is_err());
+    s.execute("table.rename", json!({"table": "Sales", "name": "A_B"})).unwrap();
+    assert!(s.doc().unwrap().wb.table("A_B").is_some());
+}
+
 #[test]
 fn undo_and_redo_keep_the_watch_window_list() {
     // Found by the command-sequence fuzzer: the list lives in the workbook but isn't an edit, so
@@ -1519,6 +1617,65 @@ fn saving_an_opened_semicolon_csv_keeps_semicolons() {
     std::fs::remove_dir_all(dir).unwrap();
 }
 
+/// A typo like `report.cvs` must not quietly write an XLSX under that name and adopt it as the
+/// document's file.
+#[test]
+#[cfg(not(target_arch = "wasm32"))]
+fn saving_to_an_unknown_extension_is_refused() {
+    #[allow(clippy::disallowed_methods)] // native-only test: a unique temp dir name
+    let nonce = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos();
+    let dir = std::env::temp_dir().join(format!("gridcraft-unknown-ext-{}-{nonce}", std::process::id()));
+    std::fs::create_dir(&dir).unwrap();
+    let mut s = s();
+    s.execute("cell.set", json!({"cell": "A1", "input": "1"})).unwrap();
+    for name in ["report.cvs", "report"] {
+        let path = dir.join(name);
+        let e = s.execute("file.save", json!({"path": path})).unwrap_err().to_string();
+        assert!(e.contains(".xlsx"), "{name}: {e}");
+        assert!(!path.exists(), "{name} was written");
+    }
+    let d = s.doc().unwrap();
+    assert!(d.path.is_none());
+    assert!(d.is_dirty());
+    assert!(s.execute("file.saveBytes", json!({"format": "foo"})).is_err());
+    s.execute("file.save", json!({"path": dir.join("report.csv")})).unwrap();
+    std::fs::remove_dir_all(dir).unwrap();
+}
+
+/// An XLSX opened by its content under an unknown extension (`budget.dat`) saves back to its own
+/// file as XLSX; a Save As to another unknown extension is still refused.
+#[test]
+#[cfg(not(target_arch = "wasm32"))]
+fn an_xlsx_opened_under_an_unknown_extension_saves_back_as_xlsx() {
+    #[allow(clippy::disallowed_methods)] // native-only test: a unique temp dir name
+    let nonce = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos();
+    let dir = std::env::temp_dir().join(format!("gridcraft-dat-{}-{nonce}", std::process::id()));
+    std::fs::create_dir(&dir).unwrap();
+    let path = dir.join("budget.dat");
+    let mut src = s();
+    src.execute("cell.set", json!({"cell": "A1", "input": "1"})).unwrap();
+    std::fs::write(&path, crate::io::save_bytes(&src.doc().unwrap().wb, "book.xlsx").unwrap()).unwrap();
+    let mut s = s();
+    s.execute("file.open", json!({"path": path})).unwrap();
+    s.execute("cell.set", json!({"cell": "A1", "input": "2"})).unwrap();
+    s.execute("file.save", json!({})).unwrap();
+    assert!(!s.doc().unwrap().is_dirty());
+    let bytes = std::fs::read(&path).unwrap();
+    assert_eq!(gridcraft_xlsx::sniff(&bytes), gridcraft_xlsx::Format::Xlsx);
+    let (wb, _) = crate::io::open_bytes("book.xlsx", &bytes).unwrap();
+    assert_eq!(wb.active().unwrap().value(CellRef::parse("A1").unwrap()), Value::Number(2.0));
+    assert!(s.execute("file.saveAs", json!({"path": dir.join("copy.foo")})).is_err());
+    assert!(!dir.join("copy.foo").exists());
+    // A text file under an unknown extension opens as CSV: Save doesn't turn it into an XLSX.
+    let notes = dir.join("notes.dat");
+    std::fs::write(&notes, "a,b\r\n").unwrap();
+    s.execute("file.open", json!({"path": notes})).unwrap();
+    s.execute("cell.set", json!({"cell": "A1", "input": "c"})).unwrap();
+    assert!(s.execute("file.save", json!({})).is_err());
+    assert_eq!(std::fs::read_to_string(&notes).unwrap(), "a,b\r\n");
+    std::fs::remove_dir_all(dir).unwrap();
+}
+
 #[test]
 fn validation_formulas_are_relative_and_see_the_new_value() {
     let mut s = s();
@@ -1617,6 +1774,17 @@ fn replacing_a_spilling_formula_clears_its_spill() {
     assert_eq!((v(&s, "A2"), v(&s, "B1")), (Value::Empty, Value::Number(0.0)));
 }
 
+#[test]
+fn clearing_a_spill_past_65536_cells_updates_a_late_dependent() {
+    let mut s = s();
+    s.execute("cell.set", json!({"cell": "A1", "input": "=SEQUENCE(65537)"})).unwrap();
+    s.execute("cell.set", json!({"cell": "C1", "input": "=A65536"})).unwrap();
+    s.execute("cell.set", json!({"cell": "C2", "input": "=A65537"})).unwrap();
+    assert_eq!(v(&s, "C2"), Value::Number(65537.0));
+    s.execute("cell.set", json!({"cell": "A1", "input": "5"})).unwrap();
+    assert_eq!((v(&s, "C1"), v(&s, "C2")), (Value::Number(0.0), Value::Number(0.0)));
+}
+
 #[test]
 fn range_ending_in_index_recalculates() {
     let mut s = s();
@@ -1696,6 +1864,23 @@ fn every_command_survives_empty_params() {
     }
 }
 
+#[test]
+fn non_object_params_do_not_panic_in_wrapper_commands() {
+    // Issue #516.
+    for cmd in ["pageLayout.themeColors", "pageLayout.background", "home.drawBorder"] {
+        for params in [json!([]), json!(5), json!("x"), json!(true)] {
+            let mut s = s();
+            let r = s.execute(cmd, params.clone());
+            assert!(!matches!(r, Err(crate::EngineError::Internal(..))), "{cmd} {params}: {r:?}");
+        }
+    }
+    // A saved script step forwards its params unchanged into the same call.
+    let mut s = s();
+    s.execute("automate.newScript", json!({"name": "bad", "commands": [{"command": "home.drawBorder", "params": []}]})).unwrap();
+    let r = s.execute("automate.runScript", json!({"name": "bad"}));
+    assert!(!matches!(r, Err(crate::EngineError::Internal(..))), "script: {r:?}");
+}
+
 fn fmt_of(s: &Session, a: &str) -> String {
     let wb = &s.doc().unwrap().wb;
     let sh = wb.active().unwrap();
@@ -2505,6 +2690,15 @@ fn fill_series_month_clamps_to_month_end() {
     assert_eq!(v(&s, "A4"), ymd(2026, 4, 15));
 }
 
+#[test]
+fn fill_series_weekday_out_of_range_step_errors() {
+    let mut s = s();
+    s.execute("cell.set", json!({"cell": "A1", "input": "45000"})).unwrap();
+    let r = s.execute("edit.fillSeries", json!({"range": "A1:A2", "direction": "columns", "type": "date", "dateUnit": "weekday", "step": 1e12}));
+    assert!(r.is_err());
+    assert_eq!(v(&s, "A2"), Value::Empty);
+}
+
 #[test]
 fn fill_series_month_leap_year() {
     let s = series_date("2028-01-31", "A1:A3", "month");
@@ -2549,6 +2743,56 @@ fn notes_comments_and_links_survive_a_json_save() {
     assert_eq!(after.cells, before.cells);
 }
 
+/// Insert › Link sorts a target as Excel's dialog does: a sheet reference, a defined name or `#…` is
+/// a place in this document, anything else an existing file or web page. A file saved as a
+/// `location` opens nothing in Excel (#800).
+#[test]
+fn links_to_files_are_saved_as_external_relationships() {
+    use std::io::Read;
+    let mut s = s();
+    s.execute("formulas.defineName", json!({"name": "Price", "refersTo": "=Sheet1!$A$1"})).unwrap();
+    s.execute("insert.table", json!({"range": "F1:G3", "name": "Sales"})).unwrap();
+    s.execute("home.insertSheet", json!({"name": "Q#1"})).unwrap();
+    s.execute("sheet.activate", json!({"sheet": 0})).unwrap();
+    let links = [
+        ("A1", "Source.xlsx", true),
+        ("A2", r"C:\Temp\Book.xlsx", true),
+        ("A3", r"..\Reports\Q1.xlsx", true),
+        ("A4", "Other.xlsx#Sheet1!A2", true),
+        ("A5", "https://example.com/a.xlsx", true),
+        ("A6", "Sheet1!B2", false),
+        ("A7", "#Sheet1!B3", false),
+        ("A8", "Price", false),
+        ("A9", "'Sheet1'!C4:D5", false),
+        ("A10", "Sales", false),
+        ("A11", "'Q#1'!B2", false),
+    ];
+    for (cell, target, _) in links {
+        s.execute("insert.link", json!({"cell": cell, "target": target})).unwrap();
+    }
+    let bytes = gridcraft_xlsx::write_xlsx(&s.doc().unwrap().wb).unwrap();
+    let mut zip = zip::ZipArchive::new(std::io::Cursor::new(bytes.clone())).unwrap();
+    let mut part = |name: &str| {
+        let mut text = String::new();
+        zip.by_name(name).unwrap().read_to_string(&mut text).unwrap();
+        text
+    };
+    let (sheet, rels) = (part("xl/worksheets/sheet1.xml"), part("xl/worksheets/_rels/sheet1.xml.rels"));
+    for (cell, target, external) in links {
+        let file = target.split_once('#').map_or(target, |(f, _)| f);
+        let as_rel = format!("Target=\"{file}\" TargetMode=\"External\"");
+        let as_location = format!("location=\"{}\"", target.trim_start_matches('#'));
+        assert_eq!(rels.contains(&as_rel), external, "{cell} {target}: {rels}");
+        assert_eq!(sheet.contains(&as_location), !external, "{cell} {target}: {sheet}");
+    }
+    assert!(sheet.contains("location=\"Sheet1!A2\""), "{sheet}");
+    let (back, _) = gridcraft_xlsx::read_xlsx(&bytes).unwrap();
+    for (cell, target, external) in links {
+        let h = &back.sheet(0).unwrap().hyperlinks[&CellRef::parse(cell).unwrap()];
+        assert_eq!((h.target.as_str(), h.external), (target.trim_start_matches('#'), external), "{cell}");
+    }
+}
+
 #[test]
 fn vertical_alignment_commands_and_roundtrip() {
     let mut s = s();
@@ -2795,3 +3039,45 @@ fn a_decrypted_workbook_never_overwrites_its_encrypted_original() {
     assert_eq!(std::fs::read(&path).unwrap(), bytes, "the encrypted original is untouched");
     std::fs::remove_dir_all(dir).unwrap();
 }
+
+#[test]
+fn subtotal_109_recalculates_when_row_height_or_autofit_reveals_rows() {
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [[1], [2], [4], [8]]})).unwrap();
+    s.execute("cell.set", json!({"cell": "C1", "input": "=SUBTOTAL(109,A1:A4)"})).unwrap();
+    s.execute("home.hideRows", json!({"rows": "2:3"})).unwrap();
+    assert_eq!(v(&s, "C1"), Value::Number(9.0));
+    // A non-zero height unhides the rows (the fuzz found the stale SUBTOTAL).
+    s.execute("home.rowHeight", json!({"rows": "2:3", "height": 60.0})).unwrap();
+    assert_eq!(v(&s, "C1"), Value::Number(15.0));
+    s.execute("home.hideRows", json!({"rows": "2:3"})).unwrap();
+    assert_eq!(v(&s, "C1"), Value::Number(9.0));
+    s.execute("home.autofitRowHeight", json!({"rows": "2:3"})).unwrap();
+    assert_eq!(v(&s, "C1"), Value::Number(15.0));
+fn paste_special_validation_copies_the_rule() {
+    let mut s = s();
+    let ok = |s: &mut Session, cell: &str, input: &str| s.execute("data.validate", json!({"cell": cell, "input": input})).unwrap()["ok"] == true;
+    s.execute("cell.set", json!({"cell": "A1", "input": "5"})).unwrap();
+    s.execute("cell.set", json!({"cell": "C3", "input": "7"})).unwrap();
+    s.execute("data.validation", json!({"range": "A1", "type": "whole", "operator": "greater", "formula1": "0"})).unwrap();
+    s.execute("edit.copy", json!({"range": "A1"})).unwrap();
+    s.execute("edit.pasteSpecial", json!({"what": "formats", "at": "E5"})).unwrap();
+    assert!(ok(&mut s, "E5", "-1"));
+    s.execute("edit.pasteSpecial", json!({"what": "validation", "at": "C3"})).unwrap();
+    assert!(!ok(&mut s, "C3", "-1"));
+    assert!(ok(&mut s, "C3", "1"));
+    assert!(!ok(&mut s, "A1", "-1"));
+    assert_eq!(s.execute("cell.get", json!({"cell": "C3"})).unwrap()["text"], json!("7"));
+}
+
+#[test]
+fn paste_special_validation_moves_relative_references() {
+    let mut s = s();
+    let ok = |s: &mut Session, cell: &str, input: &str| s.execute("data.validate", json!({"cell": cell, "input": input})).unwrap()["ok"] == true;
+    s.execute("cell.set", json!({"cell": "A1", "input": "50"})).unwrap();
+    s.execute("data.validation", json!({"range": "A1", "type": "custom", "formula1": "=A1>10"})).unwrap();
+    s.execute("edit.copy", json!({"range": "A1"})).unwrap();
+    s.execute("edit.pasteSpecial", json!({"what": "validation", "at": "C3"})).unwrap();
+    assert!(!ok(&mut s, "C3", "5"), "the pasted rule checks C3, not A1");
+    assert!(ok(&mut s, "C3", "20"));
+}