From 6b2e004c28f1fde9e50d23cd3c9c4fd5e32f61dc Mon Sep 17 00:00:00 2001
From: Linus Groh <mail@linusgroh.de>
Date: Tue, 16 Nov 2021 19:40:03 +0000
Subject: [PATCH] LibJS: Fix incorrect use of "modulo" in
 {hour,min,sec,ms}_from_time()

These all would return incorrect results for negative time values.
Also adds a missing floor() in sec_from_time().
---
 Userland/Libraries/LibJS/Runtime/Date.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/Date.cpp b/Userland/Libraries/LibJS/Runtime/Date.cpp
index b77c81828c..60e31f1359 100644
--- a/Userland/Libraries/LibJS/Runtime/Date.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Date.cpp
@@ -6,6 +6,7 @@
 
 #include <AK/StringBuilder.h>
 #include <LibCore/DateTime.h>
+#include <LibJS/Runtime/AbstractOperations.h>
 #include <LibJS/Runtime/Date.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <time.h>
@@ -282,28 +283,28 @@ u8 month_from_time(double t)
 u8 hour_from_time(double t)
 {
     // 𝔽(floor(ℝ(t / msPerHour)) modulo HoursPerDay)
-    return static_cast<u8>(fmod(floor(t / MS_PER_HOUR), HOURS_PER_DAY));
+    return static_cast<u8>(modulo(floor(t / MS_PER_HOUR), HOURS_PER_DAY));
 }
 
 // MinFromTime(t), https://tc39.es/ecma262/#eqn-MinFromTime
 u8 min_from_time(double t)
 {
     // 𝔽(floor(ℝ(t / msPerMinute)) modulo MinutesPerHour)
-    return static_cast<u8>(fmod(floor(t / MS_PER_MINUTE), MINUTES_PER_HOUR));
+    return static_cast<u8>(modulo(floor(t / MS_PER_MINUTE), MINUTES_PER_HOUR));
 }
 
 // SecFromTime(t), https://tc39.es/ecma262/#eqn-SecFromTime
 u8 sec_from_time(double t)
 {
     // 𝔽(floor(ℝ(t / msPerSecond)) modulo SecondsPerMinute)
-    return static_cast<u8>(fmod(t / MS_PER_SECOND, SECONDS_PER_MINUTE));
+    return static_cast<u8>(modulo(floor(t / MS_PER_SECOND), SECONDS_PER_MINUTE));
 }
 
 // msFromTime(t), https://tc39.es/ecma262/#eqn-msFromTime
 u16 ms_from_time(double t)
 {
     // 𝔽(ℝ(t) modulo msPerSecond)
-    return static_cast<u16>(fmod(t, MS_PER_SECOND));
+    return static_cast<u16>(modulo(t, MS_PER_SECOND));
 }
 
 // 21.4.1.11 MakeTime ( hour, min, sec, ms ), https://tc39.es/ecma262/#sec-maketime