From bd9ce3e0747a2bba3a322703c87c1d44d85deadd Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Sun, 23 Jun 2024 08:22:51 +0100
Subject: [PATCH] std::unix::os::home_dir: fallback's optimisation.

we're using a guaranteed initialised field on success.
---
 library/std/src/sys/pal/unix/os.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/library/std/src/sys/pal/unix/os.rs b/library/std/src/sys/pal/unix/os.rs
index 2e71ceceb58..3e690ce60d2 100644
--- a/library/std/src/sys/pal/unix/os.rs
+++ b/library/std/src/sys/pal/unix/os.rs
@@ -738,16 +738,17 @@ unsafe fn fallback() -> Option<OsString> {
             n => n as usize,
         };
         let mut buf = Vec::with_capacity(amt);
-        let mut passwd: libc::passwd = mem::zeroed();
+        let mut p = mem::MaybeUninit::<libc::passwd>::uninit();
         let mut result = ptr::null_mut();
         match libc::getpwuid_r(
             libc::getuid(),
-            &mut passwd,
+            p.as_mut_ptr(),
             buf.as_mut_ptr(),
             buf.capacity(),
             &mut result,
         ) {
             0 if !result.is_null() => {
+                let passwd = p.assume_init();
                 let ptr = passwd.pw_dir as *const _;
                 let bytes = CStr::from_ptr(ptr).to_bytes().to_vec();
                 Some(OsStringExt::from_vec(bytes))