Strip CSS comments from style attributes and rule declarations

Found while testing crates/svg/src/import/css.rs:20 (parse_decls / split_decls)

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

crates/svg/src/import/css.rs

@@ -18,7 +18,8 @@ pub(super) type XNode<'a, 'i> = roxmltree::Node<'a, 'i>;
 /// `name: value` declarations of a block or `style` attribute, with their `!important` flag. The
 /// `font` shorthand becomes its longhands, as usvg reads it for the rest of the drawing (#1557).
 pub(super) fn parse_decls(s: &str) -> Vec<(String, String, bool)> {
-    split_decls(s)
+    let s = strip_comments(s);
+    split_decls(&s)
         .into_iter()
         .filter_map(|d| {
             let (k, v) = d.split_once(':')?;
@@ -354,9 +355,8 @@ fn top_level_commas(list: &str) -> impl Iterator<Item = &str> {
     })
 }
 
-/// Rules from every `<style>` element, in source order.
-fn parse_sheet(css: &str, out: &mut Vec<Rule>) {
-    // Drop comments outside strings.
+/// `css` without its `/* … */` comments (those inside quoted strings stay).
+fn strip_comments(css: &str) -> String {
     let mut text = String::with_capacity(css.len());
     let mut chars = css.chars().peekable();
     let mut quote = None;
@@ -387,6 +387,12 @@ fn parse_sheet(css: &str, out: &mut Vec<Rule>) {
             text.push(c);
         }
     }
+    text
+}
+
+/// Rules from every `<style>` element, in source order.
+fn parse_sheet(css: &str, out: &mut Vec<Rule>) {
+    let text = strip_comments(css);
     let mut s = text.as_str();
     loop {
         s = s.trim_start();

crates/svg/src/import/css/tests.rs

@@ -333,3 +333,11 @@ fn not_selectors() {
         },
     );
 }
+
+#[test]
+fn decl_comments_are_stripped() {
+    let d = |k: &str, v: &str| (k.to_string(), v.to_string(), false);
+    assert_eq!(parse_decls("fill:red /* note */; stroke:blue"), [d("fill", "red"), d("stroke", "blue")]);
+    assert_eq!(parse_decls("fill:red /* a;b */ ; stroke:blue"), [d("fill", "red"), d("stroke", "blue")]);
+    assert_eq!(parse_decls("font-family:'A /* x */ B'"), [d("font-family", "'A /* x */ B'")]);
+}