Don't recalculate remaining steps, conditionally

Bug report reproduction steps: Create a new profile so that everything is set to default. Create a new card. Click Good. Open deck options and empty learning steps. Save. No go back and put 1m 10m as LS. Go back to the card and it should show 10m on the Good button. Check if old_steps is empty and if it is just use remaining steps for the new_remaining steps. Add test.
ankitects · dae · Mar 14, 2025 · Mar 8, 2025 · Mar 8, 2025 · Mar 8, 2025
commit f335c1c8fb6701c21ecb67ed3a924847fedfcb8e
diff --git a/rslib/src/card/mod.rs b/rslib/src/card/mod.rs
@@ -237,7 +237,11 @@ impl Card {
     /// greater delay, but output will be at least 1.
     fn new_remaining_steps(&self, new_steps: &[f32], old_steps: &[f32]) -> Option<u32> {
         let remaining = self.remaining_steps();
-        let new_remaining = old_steps
+
+        let new_remaining = if old_steps.len() == 0 {
+            remaining
+        } else {
+            old_steps
             .len()
             .checked_sub(remaining as usize + 1)
             .and_then(|last_index| {
@@ -249,7 +253,9 @@ impl Card {
             // no last delay or last delay is less than all new steps → all steps remain
             .unwrap_or(new_steps.len())
             // (re)learning card must have at least 1 step remaining
-            .max(1) as u32;
+            .max(1) as u32
+        };
+
         (remaining != new_remaining).then_some(new_remaining)
     }
 
@@ -493,6 +499,9 @@ mod test {
     use crate::tests::open_test_collection_with_learning_card;
     use crate::tests::open_test_collection_with_relearning_card;
     use crate::tests::DeckAdder;
+    use crate::prelude::Collection;
+    use crate::prelude::DeckId;
+    use crate::prelude::AnkiError;
 
     #[test]
     fn should_increase_remaining_learning_steps_if_new_deck_has_more_unpassed_ones() {
@@ -515,4 +524,27 @@ mod test {
         col.set_deck(&[card_id], deck.id).unwrap();
         assert_eq!(col.get_first_card().remaining_steps, 2);
     }
+
+    #[test]
+    fn should_not_recalculate_remaining_steps_if_there_are_no_old_steps() -> Result<(), AnkiError> {
+        let mut col = Collection::new();
+
+        let nt = col.get_notetype_by_name("Basic")?.unwrap();
+        let mut note = nt.new_note();
+        col.add_note(&mut note, DeckId(1))?;
+
+        let card_id = col.get_first_card().id;
+        col.set_deck(&[card_id], DeckId(1))?;
+
+        col.set_default_learn_steps(vec![1., 10.]);
+
+        let _post_answer = col.answer_good();
+
+        col.set_default_learn_steps(vec![]);
+        col.set_default_learn_steps(vec![1., 10.]);
+
+        assert_eq!(col.get_first_card().remaining_steps, 1);
+
+        Ok(())
+    }
 }