From b374adc9dbeec2cc969723dbfcb5c8ee990953bd Mon Sep 17 00:00:00 2001
From: Orson Peters <orsonpeters@gmail.com>
Date: Fri, 30 May 2025 12:13:55 +0200
Subject: [PATCH] Address review comments.

---
 library/std/src/sys/thread_local/native/lazy.rs       | 7 +++++++
 tests/ui/threads-sendsync/tls-dont-move-after-init.rs | 1 -
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/library/std/src/sys/thread_local/native/lazy.rs b/library/std/src/sys/thread_local/native/lazy.rs
index a2bf8d8b968a..b556dd9aa25e 100644
--- a/library/std/src/sys/thread_local/native/lazy.rs
+++ b/library/std/src/sys/thread_local/native/lazy.rs
@@ -84,8 +84,15 @@ where
         // access to self.value and may replace it.
         let mut old_value = unsafe { self.value.get().replace(MaybeUninit::new(v)) };
         match self.state.replace(State::Alive) {
+            // If the variable is not being recursively initialized, register
+            // the destructor. This might be a noop if the value does not need
+            // destruction.
             State::Uninitialized => D::register_dtor(self),
+
+            // Recursive initialization, we only need to drop the old value
+            // as we've already registered the destructor.
             State::Alive => unsafe { old_value.assume_init_drop() },
+
             State::Destroyed(_) => unreachable!(),
         }
 
diff --git a/tests/ui/threads-sendsync/tls-dont-move-after-init.rs b/tests/ui/threads-sendsync/tls-dont-move-after-init.rs
index f986202ab89e..54fcc32e9bd7 100644
--- a/tests/ui/threads-sendsync/tls-dont-move-after-init.rs
+++ b/tests/ui/threads-sendsync/tls-dont-move-after-init.rs
@@ -1,5 +1,4 @@
 //@ run-pass
-#![allow(stable_features)]
 //@ needs-threads
 
 use std::cell::Cell;