3 files changed, 27 insertions, 12 deletions
diff --git a/src/libstd/io/net/tcp.rs b/src/libstd/io/net/tcp.rs
index 34ccf9e617a..6d03d4a8eed 100644
--- a/src/libstd/io/net/tcp.rs
+++ b/src/libstd/io/net/tcp.rs
@@ -27,6 +27,7 @@ use io::net::addrinfo::get_host_addresses;
 use io::net::ip::SocketAddr;
 use io::{IoError, ConnectionFailed, InvalidInput};
 use io::{Reader, Writer, Listener, Acceptor};
+use io::{standard_error, TimedOut};
 use from_str::FromStr;
 use kinds::Send;
 use option::{None, Some, Option};
@@ -102,13 +103,14 @@ impl TcpStream {
     /// Note that the `addr` argument may one day be split into a separate host
     /// and port, similar to the API seen in `connect`.
     ///
-    /// # Failure
-    ///
-    /// Fails on a `timeout` of zero or negative duration.
+    /// If a `timeout` with zero or negative duration is specified then
+    /// the function returns `Err`, with the error kind set to `TimedOut`.
     #[experimental = "the timeout argument may eventually change types"]
     pub fn connect_timeout(addr: SocketAddr,
                            timeout: Duration) -> IoResult<TcpStream> {
-        assert!(timeout > Duration::milliseconds(0));
+        if timeout <= Duration::milliseconds(0) {
+            return standard_error(TimedOut);
+        }
 
         let SocketAddr { ip, port } = addr;
         let addr = rtio::SocketAddr { ip: super::to_rtio(ip), port: port };
diff --git a/src/libstd/io/net/unix.rs b/src/libstd/io/net/unix.rs
index 0b647e67a2d..99e4822afeb 100644
--- a/src/libstd/io/net/unix.rs
+++ b/src/libstd/io/net/unix.rs
@@ -29,6 +29,7 @@ use prelude::*;
 use c_str::ToCStr;
 use clone::Clone;
 use io::{Listener, Acceptor, Reader, Writer, IoResult, IoError};
+use io::{standard_error, TimedOut};
 use kinds::Send;
 use boxed::Box;
 use rt::rtio::{IoFactory, LocalIo, RtioUnixListener};
@@ -68,13 +69,14 @@ impl UnixStream {
     /// This function is similar to `connect`, except that if `timeout_ms`
     /// elapses the function will return an error of kind `TimedOut`.
     ///
-    /// # Failure
-    ///
-    /// Fails on a `timeout` of zero or negative duration.
+    /// If a `timeout` with zero or negative duration is specified then
+    /// the function returns `Err`, with the error kind set to `TimedOut`.
     #[experimental = "the timeout argument is likely to change types"]
     pub fn connect_timeout<P: ToCStr>(path: &P,
                                       timeout: Duration) -> IoResult<UnixStream> {
-        assert!(timeout > Duration::milliseconds(0));
+        if timeout <= Duration::milliseconds(0) {
+            return standard_error(TimedOut);
+        }
 
         LocalIo::maybe_raise(|io| {
             let s = io.unix_connect(&path.to_c_str(), Some(timeout.num_milliseconds() as u64));
@@ -518,14 +520,14 @@ mod tests {
     iotest!(fn connect_timeout_zero() {
         let addr = next_test_unix();
         let _a = UnixListener::bind(&addr).unwrap().listen().unwrap();
-        assert!(UnixStream::connect_timeout(&addr, Duration::milliseconds(0)).is_ok());
-    } #[should_fail])
+        assert!(UnixStream::connect_timeout(&addr, Duration::milliseconds(0)).is_err());
+    })
 
     iotest!(fn connect_timeout_negative() {
         let addr = next_test_unix();
         let _a = UnixListener::bind(&addr).unwrap().listen().unwrap();
-        assert!(UnixStream::connect_timeout(&addr, Duration::milliseconds(-1)).is_ok());
-    } #[should_fail])
+        assert!(UnixStream::connect_timeout(&addr, Duration::milliseconds(-1)).is_err());
+    })
 
     iotest!(fn close_readwrite_smoke() {
         let addr = next_test_unix();
diff --git a/src/test/run-pass/tcp-connect-timeouts.rs b/src/test/run-pass/tcp-connect-timeouts.rs
index 1bdd06ca0e9..5519963693d 100644
--- a/src/test/run-pass/tcp-connect-timeouts.rs
+++ b/src/test/run-pass/tcp-connect-timeouts.rs
@@ -96,3 +96,14 @@ iotest!(fn timeout_error() {
 
     assert!(TcpStream::connect_timeout(addr, Duration::milliseconds(1000)).is_err());
 })
+
+    iotest!(fn connect_timeout_zero() {
+        let addr = next_test_ip4();
+        assert!(TcpStream::connect_timeout(&addr, Duration::milliseconds(0)).is_err());
+    })
+
+    iotest!(fn connect_timeout_negative() {
+        let addr = next_test_ip4();
+        assert!(TcpStream::connect_timeout(&addr, Duration::milliseconds(-1)).is_err());
+    })
+