From: kenping <kenpingliu@users.noreply.github.com>
Date: Thu, 21 Apr 2022 07:59:28 +0000 (+0800)
Subject: listener: Preserve last error in evconnlistener_new_bind() before close
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d96457e13269330fabb477a9bf130dfd2e30b36a;p=libevent

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 125c7286..fc7c2c58 100644
--- 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