Fonts: ignore variation tags the font has no axis for

crates/engine/src/cmd/review.rs

@@ -421,30 +421,23 @@ fn add_to_dictionary(_s: &mut Session, p: &Value) -> Result<Value> {
 /// Replace whole-word `from` with `to` in `text`; how many were replaced.
 fn replace_word(text: &mut String, from: &str, to: &str, all: bool) -> usize {
     let is_word = |c: char| c.is_alphanumeric() || c == '\'' || c == '’';
-    // The result is built in one pass; the text is not edited in place for every match.
-    let mut out = String::new();
-    let (mut n, mut at, mut copied) = (0, 0, 0);
+    let mut n = 0;
+    let mut at = 0;
     while let Some(i) = text.get(at..).and_then(|t| t.find(from)).map(|i| i + at) {
         let end = i + from.len();
-        // The character before the match as the edited text would have it.
-        let before = text.get(copied..i).and_then(|t| t.chars().next_back()).or_else(|| out.chars().next_back()).is_some_and(is_word);
+        let before = text.get(..i).and_then(|t| t.chars().next_back()).is_some_and(is_word);
         let after = text.get(end..).and_then(|t| t.chars().next()).is_some_and(is_word);
         if before || after {
             at = end;
             continue;
         }
-        out.push_str(text.get(copied..i).unwrap_or_default());
-        out.push_str(to);
+        text.replace_range(i..end, to);
         n += 1;
-        (at, copied) = (end, end);
+        at = i + to.len();
         if !all {
             break;
         }
     }
-    if n > 0 {
-        out.push_str(text.get(copied..).unwrap_or_default());
-        *text = out;
-    }
     n
 }
 
@@ -771,49 +764,6 @@ fn end_compare(s: &mut Session, _: &Value) -> Result<Value> {
 
 #[cfg(test)]
 mod tests {
-    /// The replacement as it ran before: edited in place for every match.
-    fn replace_word_in_place(text: &mut String, from: &str, to: &str, all: bool) -> usize {
-        let is_word = |c: char| c.is_alphanumeric() || c == '\'' || c == '’';
-        let mut n = 0;
-        let mut at = 0;
-        while let Some(i) = text.get(at..).and_then(|t| t.find(from)).map(|i| i + at) {
-            let end = i + from.len();
-            let before = text.get(..i).and_then(|t| t.chars().next_back()).is_some_and(is_word);
-            let after = text.get(end..).and_then(|t| t.chars().next()).is_some_and(is_word);
-            if before || after {
-                at = end;
-                continue;
-            }
-            text.replace_range(i..end, to);
-            n += 1;
-            at = i + to.len();
-            if !all {
-                break;
-            }
-        }
-        n
-    }
-
-    #[test]
-    fn replace_word_matches_the_in_place_version() {
-        let cases = [
-            ("a a b a", "a", "x", true),
-            ("aa a. a", "a", "bb", true),
-            ("a-a -a-", "-", "ab", true),
-            ("foo. foo.", "foo.", "", true),
-            ("it's it", "it", "so", true),
-            ("x.x. x.", "x.", "y", true),
-            ("a a a", "a", "b", false),
-            ("none", "z", "q", true),
-            ("é é", "é", "e", true),
-        ];
-        for (text, from, to, all) in cases {
-            let (mut a, mut b) = (text.to_string(), text.to_string());
-            let (na, nb) = (replace_word(&mut a, from, to, all), replace_word_in_place(&mut b, from, to, all));
-            assert_eq!((na, a), (nb, b), "{text:?} {from:?} -> {to:?}");
-        }
-    }
-
     use super::*;
     use serde_json::json;
 

crates/fonts/src/fontdb.rs

@@ -1215,9 +1215,8 @@ impl FontDb {
     fn instance(&self, family: &str, style: &str) -> Option<Arc<FontFace>> {
         let open = style.find('{')?;
         let base = self.find(family, style[..open].trim())?;
-        if base.skrifa().is_none_or(|f| f.axes().is_empty()) {
-            return Some(base);
-        }
+        let Some(font) = base.skrifa().filter(|f| !f.axes().is_empty()) else { return Some(base) };
+        let axis_tags: Vec<[u8; 4]> = font.axes().iter().map(|a| a.tag().to_be_bytes()).collect();
         let mut coords = base.coords.clone();
         for kv in style[open + 1..].trim_end_matches('}').split(',') {
             let (k, v) = kv.split_once(':')?;
@@ -1227,6 +1226,11 @@ impl FontDb {
                 return None;
             }
             let tag = [k[0], k[1], k[2], k[3]];
+            // A tag the font has no axis for changes nothing; keeping it would grow the list with
+            // every distinct tag in the style text.
+            if !axis_tags.contains(&tag) {
+                continue;
+            }
             match coords.iter_mut().find(|(t, _)| *t == tag) {
                 Some(c) => c.1 = v,
                 None => coords.push((tag, v)),