Prevent MsgHdr::with_control with empty buffer causes error in macOS

rust-lang · Apr 22, 2024 · 53a293b · 53a293b
1 parent 6923954
commit 53a293b
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/src/lib.rs b/src/lib.rs
@@ -639,7 +639,11 @@ impl<'addr, 'bufs, 'control> MsgHdr<'addr, 'bufs, 'control> {
     /// Corresponds to setting `msg_control` and `msg_controllen` on Unix and
     /// `Control` on Windows.
     pub fn with_control(mut self, buf: &'control [u8]) -> Self {
-        let ptr = buf.as_ptr() as *mut _;
+        let ptr = if buf.is_empty() {
+            std::ptr::null_mut()
+        } else {
+            buf.as_ptr() as *mut _
+        };
         sys::set_msghdr_control(&mut self.inner, ptr, buf.len());
         self
     }

diff --git a/tests/socket.rs b/tests/socket.rs
@@ -755,7 +755,10 @@ fn sendmsg() {
 
     let bufs = &[IoSlice::new(DATA)];
     let addr_b = socket_b.local_addr().unwrap();
-    let msg = socket2::MsgHdr::new().with_addr(&addr_b).with_buffers(bufs);
+    let msg = socket2::MsgHdr::new()
+        .with_addr(&addr_b)
+        .with_buffers(bufs)
+        .with_control(&[]);
     let sent = socket_a.sendmsg(&msg, 0).unwrap();
     assert_eq!(sent, DATA.len());