From 28dc0654fa5a6bd8237d92caa60d605ac932ef7b Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Tue, 25 Apr 2023 22:20:04 +1000
Subject: [PATCH] fix error handling when setting socket options (#102)

Both sockopt and control errors can't exist at the same time, but control errors should occur first, and so are given precedence.

Fixes #101
---
 control_unix.go    | 14 ++++++--------
 control_windows.go |  6 +++++-
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/control_unix.go b/control_unix.go
index 06a0572..4197d1f 100644
--- a/control_unix.go
+++ b/control_unix.go
@@ -8,18 +8,16 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func Control(network, address string, c syscall.RawConn) error {
-	var err error
-	c.Control(func(fd uintptr) {
+func Control(network, address string, c syscall.RawConn) (err error) {
+	controlErr := c.Control(func(fd uintptr) {
 		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
 		if err != nil {
 			return
 		}
-
 		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
-		if err != nil {
-			return
-		}
 	})
-	return err
+	if controlErr != nil {
+		err = controlErr
+	}
+	return
 }
diff --git a/control_windows.go b/control_windows.go
index 840534c..c45e43f 100644
--- a/control_windows.go
+++ b/control_windows.go
@@ -7,7 +7,11 @@ import (
 )
 
 func Control(network, address string, c syscall.RawConn) (err error) {
-	return c.Control(func(fd uintptr) {
+	controlErr := c.Control(func(fd uintptr) {
 		err = windows.SetsockoptInt(windows.Handle(fd), windows.SOL_SOCKET, windows.SO_REUSEADDR, 1)
 	})
+	if controlErr != nil {
+		err = controlErr
+	}
+	return
 }