---

yaml
---
r: 142699
b: refs/heads/try2
c: 413d51e
h: refs/heads/master
i:
  142697: c08beb3
  142695: 3f97cbd
v: v3

Author: brson

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 6fb92f8cab03824a52da6ad23060fe791928dcc9
+refs/heads/try2: 413d51e32debf0c3f7dda2434b64d73585df21ef
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/libstd/rt/uv/net.rs

@@ -392,6 +392,13 @@ impl UdpWatcher {
 
         extern fn recv_cb(handle: *uvll::uv_udp_t, nread: ssize_t, buf: Buf,
                           addr: *uvll::sockaddr, flags: c_uint) {
+            // When there's no data to read the recv callback can be a no-op.
+            // This can happen if read returns EAGAIN/EWOULDBLOCK. By ignoring
+            // this we just drop back to kqueue and wait for the next callback.
+            if nread == 0 {
+                return;
+            }
+
             rtdebug!("buf addr: %x", buf.base as uint);
             rtdebug!("buf len: %d", buf.len as int);
             let mut udp_watcher: UdpWatcher = NativeHandle::from_native_handle(handle);