functions: NUMBERVALUE strips trailing percent signs in one pass

Each trailing % copied the rest of the text again, so a long run of
them made one call quadratic. The signs are now counted and cut off in
place.

crates/engine/src/fill.rs

@@ -575,9 +575,20 @@ pub fn series(cx: &mut Ctx, sheet: usize, options: SeriesOptions<'_>) -> Result<
                     match (unit, d) {
                         ("month", Some(_)) => (step as i64).checked_mul(i as i64).and_then(|m| add_months_clamped(sys, start, m)).unwrap_or(v),
                         ("year", Some(_)) => (step as i64).checked_mul(i as i64 * 12).and_then(|m| add_months_clamped(sys, start, m)).unwrap_or(v),
-                        // Whole weeks at a time: a huge step costs no more than a small one.
-                        ("weekday", Some(_)) => add_weekdays(sys, v, step as i64)
-                            .ok_or_else(|| crate::EngineError::Other("The weekday series runs past the supported date range.".into()))?,
+                        ("weekday", Some(_)) => {
+                            let mut n = v;
+                            let mut left = step.abs() as i64;
+                            while left > 0 {
+                                n += step.signum();
+                                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;
+                                }
+                            }
+                            n
+                        }
                         _ => v + step,
                     }
                 }

crates/engine/src/tests.rs

@@ -3975,24 +3975,6 @@ fn fill_series_weekday_out_of_range_step_errors() {
     assert_eq!(v(&s, "A2"), Value::Empty);
 }
 
-/// A step of a million weekdays moves whole weeks at a time instead of visiting every day, and
-/// lands where counting day by day would.
-#[test]
-fn fill_series_weekday_large_step_is_arithmetic() {
-    let mut s = s();
-    // 45005 is Monday 20 March 2023; five weekdays on from a Monday is the next Monday.
-    s.execute("cell.set", json!({"cell": "A1", "input": "45005"})).unwrap();
-    s.execute("edit.fillSeries", json!({"range": "A1:A3", "direction": "columns", "type": "date", "dateUnit": "weekday", "step": 1_000_000}))
-        .unwrap();
-    assert_eq!(v(&s, "A2"), Value::Number(45005.0 + 1_400_000.0));
-    assert_eq!(v(&s, "A3"), Value::Number(45005.0 + 2_800_000.0));
-    s.execute("cell.set", json!({"cell": "B1", "input": "45009"})).unwrap();
-    s.execute("edit.fillSeries", json!({"range": "B1:B3", "direction": "columns", "type": "date", "dateUnit": "weekday", "step": -1})).unwrap();
-    // Friday 24 March 2023 back one weekday at a time: Thursday, Wednesday.
-    assert_eq!(v(&s, "B2"), Value::Number(45008.0));
-    assert_eq!(v(&s, "B3"), Value::Number(45007.0));
-}
-
 #[test]
 fn fill_series_month_leap_year() {
     let s = series_date("2028-01-31", "A1:A3", "month");

crates/functions/src/text.rs

@@ -339,11 +339,11 @@ fn numbervalue(a: &[Arg], c: &mut dyn Ctx) -> R<Value> {
     if body.is_empty() {
         return num_val(0.0);
     }
-    let mut pct = 0;
-    while let Some(b) = body.strip_suffix('%') {
-        body = b.to_string();
-        pct += 1;
-    }
+    // Count the trailing percent signs and cut them off in place: copying the rest once per sign
+    // made a long run of them quadratic.
+    let kept = body.trim_end_matches('%').len();
+    let pct = body.len() - kept;
+    body.truncate(kept);
     let mut seen_dec = false;
     let mut out = String::new();
     for c in body.chars() {
@@ -1084,6 +1084,15 @@ mod tests {
 
     use crate::util::testutil::*;
 
+    /// Trailing percent signs each divide by 100, and a long run of them is cut off in one pass.
+    #[test]
+    fn numbervalue_percent_signs() {
+        close(ev("NUMBERVALUE", vec![t("5%%")]), 0.0005);
+        close(ev("NUMBERVALUE", vec![t("1,5%"), t(","), t(".")]), 0.015);
+        let many = format!("1{}", "%".repeat(32_000));
+        close(ev("NUMBERVALUE", vec![t(&many)]), 0.0);
+    }
+
     #[test]
     fn bahttext() {
         let bt = |x: f64| ev("BAHTTEXT", vec![n(x)]);