From 7aaf7624b78bc1977aa102dfe4aee952f5cfdf48 Mon Sep 17 00:00:00 2001
From: Pete Schwamb <pete@schwamb.net>
Date: Wed, 30 Aug 2023 12:51:39 -0500
Subject: [PATCH] Prevent negative duration doses, which can happen if the
 phone clock is changed

---
 MinimedKit/PumpManager/UnfinalizedDose.swift | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/MinimedKit/PumpManager/UnfinalizedDose.swift b/MinimedKit/PumpManager/UnfinalizedDose.swift
index 6298588..de9d0f7 100644
--- a/MinimedKit/PumpManager/UnfinalizedDose.swift
+++ b/MinimedKit/PumpManager/UnfinalizedDose.swift
@@ -117,7 +117,9 @@ public struct UnfinalizedDose: RawRepresentable, Equatable, CustomStringConverti
         
         let programmedUnits = units
         self.programmedUnits = programmedUnits
-        let newDuration = date.timeIntervalSince(startTime)
+
+        // Guard against negative duration if clock has changed
+        let newDuration = max(0, date.timeIntervalSince(startTime))
 
         switch doseType {
         case .bolus: