fix: keep semicolons inside xctrace symbols

src/lib.rs

@@ -521,7 +521,9 @@ fn demangle_stream<R: BufRead, W: Write>(input: &mut R, output: &mut W) -> std::
             let mangled = String::from_utf8_lossy(attr.value.as_ref());
 
             if let Ok(demangled) = try_demangle(&mangled) {
-                let demangled = format!("{demangled:#}");
+                // Folded stacks use semicolons as frame separators. Keep semicolons that
+                // occur inside Rust array types from being interpreted as extra frames.
+                let demangled = format!("{demangled:#}").replace(';', ":");
                 attr.value = match quick_xml::escape::escape(demangled) {
                     Cow::Borrowed(s) => Cow::Borrowed(s.as_bytes()),
                     Cow::Owned(s) => Cow::Owned(s.into_bytes()),
@@ -818,3 +820,24 @@ impl FlamegraphOptions {
         options
     }
 }
+
+#[cfg(all(test, target_os = "macos"))]
+mod tests {
+    use std::io::Cursor;
+
+    use super::demangle_stream;
+
+    #[test]
+    fn keeps_array_types_inside_one_folded_frame() {
+        let mut input =
+            Cursor::new(br#"<frame name="_RINvCscPdqpYx78pI_8rust_out3fooAhj2_EB2_"></frame>"#);
+        let mut output = Vec::new();
+
+        demangle_stream(&mut input, &mut output).unwrap();
+
+        assert_eq!(
+            String::from_utf8(output).unwrap(),
+            r#"<frame name="rust_out::foo::&lt;[u8: 2]&gt;"></frame>"#
+        );
+    }
+}