fix: don't ignore all but the first resolved socket addresses

Summary

• fix: don't ignore all but the first resolved socket addresses

Close #193 (closed)

This bug was introduced during refactoring when the non-blocking tcp connect was introduced.

Ensure that

• New code is covered by tests
• API is documented
• Changelog is up to date
• Version is bumped in the appropriate Cargo.toml files

tarantool/src/network/client/tcp.rs

@@ -169,11 +169,13 @@ impl TcpStream {
             // If no error, then connection is established
         };
 
+        // If this allocation panics the fd will still be closed
+        let result = Self {
+            fd: Rc::new(Cell::new(None)),
+        };
         // Now TcpStream owns the fd and takes responsibility of closing it.
-        let fd = fd.into_inner();
-        return Ok(Self {
-            fd: Rc::new(Cell::new(Some(fd))),
-        });
+        result.fd.set(Some(fd.into_inner()));
+        return Ok(result);
     }
 
     #[inline(always)]
@@ -258,6 +260,8 @@ fn nonblocking_socket(kind: libc::c_int) -> io::Result<AutoCloseFd> {
 /// A wrapper around a raw file descriptor, which automatically closes the
 /// descriptor if dropped.
 /// Use [`Self::into_inner`] to disable the automatic close on drop.
+///
+/// TODO: consider using [`std::os::fd::OwnedFd`] instead
 struct AutoCloseFd(RawFd);
 
 impl AutoCloseFd {
@@ -659,7 +663,7 @@ mod tests {
     async fn read_timeout() {
         let mut stream = TcpStream::connect_timeout("localhost", listen_port(), _10_SEC).unwrap();
         // Read greeting
-        let mut buf = vec![0; 128];
+        let mut buf = vec![0; 4096];
         assert_eq!(
             stream
                 .read_exact(&mut buf)
@@ -843,10 +847,10 @@ mod tests {
         unsafe { libc::close(fd) };
     }
 
-    fn get_socket_fds() -> Vec<u32> {
+    fn get_socket_fds() -> HashSet<u32> {
         use std::os::unix::fs::FileTypeExt;
 
-        let mut res = vec![];
+        let mut res = HashSet::new();
         for entry in std::fs::read_dir("/dev/fd/").unwrap() {
             let Ok(entry) = entry else {
                 continue;
@@ -862,9 +866,8 @@ mod tests {
             // Yay rust!
             let fd_str = fd_path.file_name().unwrap();
             let fd: u32 = fd_str.to_str().unwrap().parse().unwrap();
-            res.push(fd);
+            res.insert(fd);
         }
-        res.sort_unstable();
         res
     }
 
@@ -881,6 +884,7 @@ mod tests {
         // XXX: this is a bit unreliable, because tarantool is spawning a bunch
         // of other threads which may or may not be creating and closing fds,
         // so we may want to remove this test at some point
-        assert_eq!(fds_before, fds_after)
+        let new_fds: Vec<_> = fds_after.difference(&fds_before).copied().collect();
+        assert!(dbg!(new_fds.is_empty()));
     }
 }