apply proper sorting for catch objects

src/catch/convert.rs

@@ -8,7 +8,7 @@ use crate::{
         hit_object::{HitObject, HitObjectKind, HoldNote, Spinner},
         mode::ConvertStatus,
     },
-    util::{float_ext::FloatExt, random::Random, sort},
+    util::{float_ext::FloatExt, random::Random, sort::TandemSorter},
 };
 
 use super::{
@@ -75,12 +75,21 @@ pub fn convert_objects(
         palpable_objects.extend(new_objects);
     }
 
-    sort::csharp(&mut palpable_objects, |a, b| {
+    // Initializing hyper dashes requires objects to be sorted by C#'s unstable
+    // sort. After that, we unsort the objects again and then apply a stable
+    // sort to have the correct order for generating difficulty objects.
+    // Required e.g. due to map /b/102923.
+    let mut sorter = TandemSorter::new_unstable(&mut palpable_objects, |a, b| {
         a.start_time.total_cmp(&b.start_time)
     });
 
+    sorter.sort(&mut palpable_objects);
+
     initialize_hyper_dash(cs, &mut palpable_objects);
 
+    sorter.unsort(&mut palpable_objects);
+    palpable_objects.sort_by(|a, b| a.start_time.total_cmp(&b.start_time));
+
     palpable_objects
 }