listener: Preserve last error in evconnlistener_new_bind() before close

In function evconnlistener_new_bind() after go to "err:", The
evutil_closesocket() would clear the error code( I found this under
Windows ). User can not use EVUTIL_SOCKET_ERROR() to get the
evconnlistener_new_bind()'s failing error.

I add a err_code variable to store and restore the last error code.

v2: rebased by azat to make the patch simpler

diff --git a/listener.c b/listener.c
index 125c7286f09141abcb58248776f2f2eeeae3176b..fc7c2c583c49a7f6afa21f3dbb5168bd6d38a6c5 100644 (file)
--- a/listener.c
+++ b/listener.c
@@ -275,8 +275,13 @@ evconnlistener_new_bind(struct event_base *base, evconnlistener_cb cb,
 
        return listener;
 err:
-       evutil_closesocket(fd);
-       return NULL;
+       {
+               int saved_errno = EVUTIL_SOCKET_ERROR();
+               evutil_closesocket(fd);
+               if (saved_errno)
+                       EVUTIL_SET_SOCKET_ERROR(saved_errno);
+               return NULL;
+       }
 }
 
 void