Prevent future potential UB in unix wrapper for getpwuid() (#104)

src/os/unix.rs

@@ -238,7 +238,6 @@ fn getpwuid(name: Name) -> Result<OsString> {
  const BUF_SIZE: usize = 16_384; // size from the man page
  let mut buffer = mem::MaybeUninit::<[u8; BUF_SIZE]>::uninit();
  let mut passwd = mem::MaybeUninit::<PassWd>::uninit();
- let mut _passwd = mem::MaybeUninit::<*mut PassWd>::uninit();
 
  // Get PassWd `struct`.
  let passwd = unsafe {
@@ -251,6 +250,7 @@ fn getpwuid(name: Name) -> Result<OsString> {
  target_os = "openbsd",
  ))]
  {
+ let mut _passwd = mem::MaybeUninit::<*mut PassWd>::uninit();
  let ret = getpwuid_r(
  geteuid(),
  passwd.as_mut_ptr(),
@@ -268,6 +268,7 @@ fn getpwuid(name: Name) -> Result<OsString> {
  if _passwd.is_null() {
  return Err(super::err_null_record());
  }
+ passwd.assume_init()
  }
 
  #[cfg(target_os = "illumos")]
@@ -282,9 +283,8 @@ fn getpwuid(name: Name) -> Result<OsString> {
  if ret.is_null() {
  return Err(Error::last_os_error());
  }
+ passwd.assume_init()
  }
-
- passwd.assume_init()
  };
 
  // Extract names.