From 13691e95e5148db55e370b195dc7b9e7ed5414ed Mon Sep 17 00:00:00 2001
From: Marco Arnulfo <marcoarnulfo1@gmail.com>
Date: Wed, 14 Oct 2026 12:51:05 +0200
Subject: [PATCH] Remove Duplicates: a Sheet! prefix on the range works on that
 sheet, not the active one (refs #1283)

---
 crates/engine/src/cmd/data.rs | 22 +++++++++++++++++++---
 crates/engine/src/tests.rs    | 23 +++++++++++++++++++++++
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/crates/engine/src/cmd/data.rs b/crates/engine/src/cmd/data.rs
index 383624b70..2e7b379d0 100644
--- a/crates/engine/src/cmd/data.rs
+++ b/crates/engine/src/cmd/data.rs
@@ -147,6 +147,23 @@ fn data_range(s: &Session, p: &Json) -> Result<RangeRef> {
     Ok(current_region(sh, d.selection.active))
 }
 
+/// The sheet and range a data command works on: the sheet `sheet` or a `Sheet!` prefix on `range`
+/// names, else the active one. The selection belongs to the active sheet, so another sheet needs `range`.
+fn data_target(s: &Session, p: &Json, cmd: &str) -> Result<(usize, RangeRef)> {
+    let sheet = target_sheet(s, p)?;
+    let d = s.doc()?;
+    if let Some(t) = str_param(p, "range")
+        && let (Some(name), _) = split_sheet(t)
+        && d.wb.sheet_index(&name) != Some(sheet)
+    {
+        return Err(bad(cmd, format!("`{t}` names a sheet other than `sheet`")));
+    }
+    if sheet != d.wb.active_sheet && p.get("range").is_none() {
+        return Err(bad(cmd, "missing `range`: the selection is on the active sheet"));
+    }
+    Ok((sheet, data_range(s, p)?))
+}
+
 /// Excel's header guess: the first row is text over a column of numbers, or is bold.
 fn guess_header(wb: &Workbook, sh: &Sheet, r: RangeRef) -> bool {
     if let Some(t) = sh.table_at(r.start) {
@@ -736,9 +753,9 @@ fn sort_key(v: &Value) -> (u8, i64, String) {
 // ---------------------------------------------------------------- tools
 
 fn remove_duplicates(s: &mut Session, p: &Json) -> Result<Json> {
-    let r = data_range(s, p)?;
+    let (sheet, r) = data_target(s, p, "data.removeDuplicates")?;
     let d = s.doc()?;
-    let sh = d.wb.active().ok_or(EngineError::NoDocument)?;
+    let sh = d.wb.sheet(sheet).ok_or(EngineError::NoDocument)?;
     // Rows and columns past the data are blank: only the part with data is compared (whole
     // columns compared a million blank rows and reported them as removed duplicates).
     let r = sh.used_range().and_then(|u| r.intersection(&u)).unwrap_or(RangeRef::cell(r.start));
@@ -748,7 +765,6 @@ fn remove_duplicates(s: &mut Session, p: &Json) -> Result<Json> {
         .and_then(Json::as_array)
         .map(|a| a.iter().filter_map(|c| col_param(Some(c), r.start.col)).collect())
         .unwrap_or_else(|| (r.start.col..=r.end.col).collect());
-    let sheet = d.wb.active_sheet;
     let start = r.start.row + header as u32;
     let mut removed = 0;
     edit(s, |cx| {
diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index ae499a189..19a512d73 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -1039,6 +1039,29 @@ fn remove_duplicates_compares_shown_text() {
     assert_eq!(r["removed"], 1);
 }
 
+#[test]
+fn remove_duplicates_with_a_sheet_prefix_works_on_the_named_sheet() {
+    let col = |s: &Session, sheet: &str| -> Vec<Value> {
+        let wb = &s.doc().unwrap().wb;
+        let sh = wb.sheet(wb.sheet_index(sheet).unwrap()).unwrap();
+        (1..=3).map(|r| sh.value(CellRef::new(r, 0))).collect()
+    };
+    let mut s = s();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["Name"], ["a"], ["a"], ["a"]]})).unwrap();
+    s.execute("home.insertSheet", json!({"name": "Prices"})).unwrap();
+    s.execute("range.setValues", json!({"range": "Prices!A1", "values": [["Item"], ["p1"], ["p1"], ["p2"]]})).unwrap();
+    s.execute("sheet.activate", json!({"sheet": "Sheet1"})).unwrap();
+    let r = s.execute("data.removeDuplicates", json!({"range": "Prices!A1:A4", "header": true})).unwrap();
+    assert_eq!(r["removed"], 1);
+    assert_eq!(col(&s, "Prices"), [Value::from("p1"), Value::from("p2"), Value::Empty]);
+    assert_eq!(col(&s, "Sheet1"), ["a", "a", "a"].map(Value::from));
+    // The selection belongs to the active sheet, so another sheet needs its range.
+    assert!(s.execute("data.removeDuplicates", json!({"sheet": "Prices", "header": true})).is_err());
+    assert!(s.execute("data.removeDuplicates", json!({"sheet": "Sheet1", "range": "Prices!A1:A4", "header": true})).is_err());
+    assert!(s.execute("data.removeDuplicates", json!({"range": "Nowhere!A1:A4", "header": true})).is_err());
+    assert_eq!(col(&s, "Sheet1"), ["a", "a", "a"].map(Value::from));
+}
+
 #[test]
 fn formatting_and_styles() {
     let mut s = s();