From efb4d974678aec8ed55e4001358c97243cc6cbab Mon Sep 17 00:00:00 2001
From: cheatfate <ka@hardcore.kiev.ua>
Date: Tue, 14 Jun 2016 17:22:34 +0300
Subject: [PATCH] Resolve #4334

---
 lib/pure/selectors.nim | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/pure/selectors.nim b/lib/pure/selectors.nim
index 89e92c1333..098b78c959 100644
--- a/lib/pure/selectors.nim
+++ b/lib/pure/selectors.nim
@@ -132,11 +132,12 @@ elif defined(linux):
         s.fds[fd].events = events
 
   proc unregister*(s: var Selector, fd: SocketHandle) =
-    if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fd, nil) != 0:
-      let err = osLastError()
-      if err.cint notin {ENOENT, EBADF}:
-        # TODO: Why do we sometimes get an EBADF? Is this normal?
-        raiseOSError(err)
+    if s.fds[fd].events != {}:
+      if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fd, nil) != 0:
+        let err = osLastError()
+        if err.cint notin {ENOENT, EBADF}:
+          # TODO: Why do we sometimes get an EBADF? Is this normal?
+          raiseOSError(err)
     s.fds.del(fd)
 
   proc close*(s: var Selector) =