From e2699831505a13354a0bb294f0dc17cb483528eb Mon Sep 17 00:00:00 2001
From: Jarrett Ye <jarrett.ye@outlook.com>
Date: Sun, 14 Apr 2024 17:08:01 +0800
Subject: [PATCH] return current weights if fsrs_items is zero

---
 rslib/src/scheduler/fsrs/weights.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rslib/src/scheduler/fsrs/weights.rs b/rslib/src/scheduler/fsrs/weights.rs
index 19c13b51c..93957a69b 100644
--- a/rslib/src/scheduler/fsrs/weights.rs
+++ b/rslib/src/scheduler/fsrs/weights.rs
@@ -65,6 +65,12 @@ impl Collection {
             fsrs_items_for_training(revlogs.clone(), timing.next_day_at, ignore_revlogs_before);
 
         let fsrs_items = items.len() as u32;
+        if fsrs_items == 0 {
+            return Ok(ComputeFsrsWeightsResponse {
+                weights: current_weights.to_vec(),
+                fsrs_items,
+            });
+        }
         anki_progress.update(false, |p| {
             p.current_preset = current_preset;
             p.total_presets = total_presets;