From 62053cac61a08383abfadf0a3ebac7ca74943ce3 Mon Sep 17 00:00:00 2001
From: vladimirkl <72238+vladimirkl@users.noreply.github.com>
Date: Sat, 15 Mar 2025 20:29:07 +0300
Subject: [PATCH 1/2] Fix ZIO#timeoutTo inheriting wrong value from
 FiberRef#locally (#9693)

---
 core-tests/shared/src/test/scala/zio/FiberRefSpec.scala | 9 +++++++++
 core/shared/src/main/scala/zio/ZIO.scala                | 6 +++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala b/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala
index e6dd180dce10..3561f8fe690b 100644
--- a/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala
+++ b/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala
@@ -101,6 +101,15 @@ object FiberRefSpec extends ZIOBaseSpec {
           value      <- fiberRef.get
         } yield assert(localValue)(equalTo(update)) && assert(value)(equalTo(initial))
       },
+      test("`locally` restores parent's value after timeout") {
+        for {
+          fiberRef <- FiberRef.make(initial)
+          child    <- fiberRef.locally(update)(ZIO.sleep(10.seconds)).timeout(1.second).fork
+          _        <- TestClock.adjust(1.second)
+          _        <- child.join
+          value    <- fiberRef.get
+        } yield assert(value)(equalTo(initial))
+      },
       test("`modify` changes value") {
         for {
           fiberRef <- FiberRef.make(initial)
diff --git a/core/shared/src/main/scala/zio/ZIO.scala b/core/shared/src/main/scala/zio/ZIO.scala
index 9bf8f6cae723..56e64674557f 100644
--- a/core/shared/src/main/scala/zio/ZIO.scala
+++ b/core/shared/src/main/scala/zio/ZIO.scala
@@ -5603,14 +5603,14 @@ object ZIO extends ZIOCompanionPlatformSpecific with ZIOCompanionVersionSpecific
         self.raceFibersWith[R, Nothing, E, Unit, B1](ZIO.sleep(duration).interruptible)(
           (winner, loser) =>
             winner.await.flatMap { exit =>
-              winner.inheritAll *> loser.interruptAs(parentFiberId) *> exit.mapExit(f)
+              loser.interruptAs(parentFiberId) *> winner.inheritAll *> exit.mapExit(f)
             },
           (winner, loser) =>
             winner.await.flatMap {
               case e: Exit.Failure[Nothing] =>
-                loser.inheritAll *> loser.interruptAs(parentFiberId) *> e
+                loser.interruptAs(parentFiberId) *> loser.inheritAll *> e
               case _ =>
-                loser.inheritAll *> loser.interruptAs(parentFiberId).as(b())
+                loser.interruptAs(parentFiberId) *> loser.inheritAll.as(b())
             },
           null,
           FiberScope.global

From c145e8bc02fcfe86429bccf5622f419ccdeeacc9 Mon Sep 17 00:00:00 2001
From: Adam Hearn <22334119+hearnadam@users.noreply.github.com>
Date: Sat, 15 Mar 2025 15:03:01 -0700
Subject: [PATCH 2/2] use ZIO.never

---
 core-tests/shared/src/test/scala/zio/FiberRefSpec.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala b/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala
index 3561f8fe690b..89d75b00c44d 100644
--- a/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala
+++ b/core-tests/shared/src/test/scala/zio/FiberRefSpec.scala
@@ -104,7 +104,7 @@ object FiberRefSpec extends ZIOBaseSpec {
       test("`locally` restores parent's value after timeout") {
         for {
           fiberRef <- FiberRef.make(initial)
-          child    <- fiberRef.locally(update)(ZIO.sleep(10.seconds)).timeout(1.second).fork
+          child    <- fiberRef.locally(update)(ZIO.never).timeout(1.second).fork
           _        <- TestClock.adjust(1.second)
           _        <- child.join
           value    <- fiberRef.get