From 0ede26f5bcb98b3ef7b28baee3a436cd86483158 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20Mittelst=C3=A4dt?=
 <62167861+TheGalitube@users.noreply.github.com>
Date: Thu, 29 Oct 2026 09:05:48 +0000
Subject: [PATCH] Clamp the minimum beat before conversion

Found while testing crates/time/src/tempo.rs:304

Co-Authored-By: GPT-6-Luna <noreply@openai.com>
---
 crates/time/src/tempo.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/crates/time/src/tempo.rs b/crates/time/src/tempo.rs
index 6aaa50b8..46c05064 100644
--- a/crates/time/src/tempo.rs
+++ b/crates/time/src/tempo.rs
@@ -301,7 +301,7 @@ impl TempoMap {
     pub fn tick_at_bar_beat(&self, bb: BarBeat) -> i64 {
         let start = self.bar_start_tick(bb.bar);
         let m = self.meter_at_tick(start);
-        start.saturating_add((bb.beat - 1).max(0).saturating_mul(m.ticks_per_beat())).saturating_add(bb.tick)
+        start.saturating_add(bb.beat.saturating_sub(1).max(0).saturating_mul(m.ticks_per_beat())).saturating_add(bb.tick)
     }
 
     pub fn bar_beat_at(&self, s: Samples, sr: SampleRate) -> BarBeat {
@@ -344,6 +344,12 @@ mod tests {
         assert_eq!(m.bar_start_tick(0), -TICKS_PER_QUARTER * 4);
     }
 
+    #[test]
+    fn minimum_beat_is_clamped_without_overflow() {
+        let m = TempoMap::default();
+        assert_eq!(m.tick_at_bar_beat(BarBeat { bar: 1, beat: i64::MIN, tick: 0 }), 0);
+    }
+
     #[test]
     fn bar_beat_at_min_tick_does_not_overflow() {
         let m = TempoMap::default();