Try to parse TcpStream::connect 'host' parameter as an IP.

Fall back to get_host_addresses to try a DNS lookup if we can't
parse it as an IP address.

Author: thomaslee

src/libstd/io/net/tcp.rs

@@ -63,7 +63,10 @@ impl TcpStream {
     /// `host` can be a hostname or IP address string. If no error is
     /// encountered, then `Ok(stream)` is returned.
     pub fn connect(host: &str, port: u16) -> IoResult<TcpStream> {
-        let addresses = try!(get_host_addresses(host));
+        let addresses = match FromStr::from_str(host) {
+            Some(addr) => vec!(addr),
+            None => try!(get_host_addresses(host))
+        };
         let mut err = IoError{
             kind: ConnectionFailed,
             desc: "no addresses found for hostname",

src/test/run-pass/tcp-stress.rs

@@ -37,11 +37,9 @@ fn main() {
         unsafe { libc::exit(1) }
     });
 
-    let host = "127.0.0.1";
-    let port = 0;
     let (tx, rx) = channel();
     spawn(proc() {
-        let mut listener = TcpListener::bind(host, port).unwrap();
+        let mut listener = TcpListener::bind("127.0.0.1", 0).unwrap();
         tx.send(listener.socket_name().unwrap());
         let mut acceptor = listener.listen();
         loop {
@@ -57,15 +55,15 @@ fn main() {
         }
     });
     let addr = rx.recv();
-    let host = addr.ip.to_str();
-    let port = addr.port;
 
     let (tx, rx) = channel();
     for _ in range(0, 1000) {
         let tx = tx.clone();
         let mut builder = TaskBuilder::new();
         builder.opts.stack_size = Some(32 * 1024);
         builder.spawn(proc() {
+            let host = addr.ip.to_str();
+            let port = addr.port;
             match TcpStream::connect(host, port) {
                 Ok(stream) => {
                     let mut stream = stream;