Calc: SUBTOTAL(10x) recalculates when Row Height, AutoFit Row Height or Ungroup reveal rows

home.rowHeight, home.autofitRowHeight and data.ungroup change row hidden
state without marking the edit structural, so SUBTOTAL(101-111) kept a stale
value. Found by the command-sequence fuzz (seed 3).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ROADMAP.md

@@ -132,6 +132,7 @@ Ranked; estimates in Opus 5.5 agent-hours. Detail and the full beta-gate list in
 
 | Date | What landed |
 |---|---|
+| 2026-10-12 | SUBTOTAL(109) over hidden rows recalculates after Row Height, AutoFit Row Height and Ungroup reveal rows (found by the command-sequence fuzz) |
 | 2026-10-12 | File › Print selects a system printer, copies, duplex and grayscale, submits PDF jobs through craft-print on a worker and shows spooler errors; browser printing and PDF export remain available |
 | 2026-10-11 | Command-sequence fuzzing: random command sequences checked against undo/redo, XLSX round-trip and full recalculation; fixes for the table, legacy-array, spill, AutoSum, Watch Window and sheet-copy bugs it found |
 | 2026-10-11 | Password-protected workbooks open: GridCraft asks for the password and decrypts Agile and Standard encryption (#11) |

crates/engine/src/cmd/data.rs

@@ -1129,6 +1129,7 @@ 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)
     })
 }

crates/engine/src/cmd/format.rs

@@ -953,6 +953,7 @@ 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)
     })
 }
@@ -1069,6 +1070,7 @@ 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)
     })
 }

crates/engine/src/tests.rs

@@ -2795,3 +2795,19 @@ 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));
+}