net: fix socket duplication error handling on Windows

Calls to dupSocket may fail, but the error is not properly handled
because the surrounding code incorrectly checks for nil error instead
of non-nil error.

I'm not aware of any code paths that would trigger this error, and
I haven't been able to create a test case that does so, but this
change fixes the error handling to correctly propagate any errors
from dupSocket.

Change-Id: I5ffd3cbe8ed58a83634f3b97c0878a7c73e0505e
Reviewed-on: https://go-review.googlesource.com/c/go/+/734821
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>

diff --git a/src/net/fd_windows.go b/src/net/fd_windows.go
index 52985be8e65403df188fef357abed6640528a84a..c28ce045c47811202395fb9477c28325234f8e10 100644 (file)
--- a/src/net/fd_windows.go
+++ b/src/net/fd_windows.go
@@ -248,7 +248,7 @@ func (fd *netFD) dup() (*os.File, error) {
        err := fd.pfd.RawControl(func(fd uintptr) {
                h, syserr = dupSocket(syscall.Handle(fd))
        })
-       if err != nil {
+       if err == nil {
                err = syserr
        }
        if err != nil {

diff --git a/src/net/file_windows.go b/src/net/file_windows.go
index b4eb00e56448a578d509702f71aaa09edc5b3f6a..6a6305035a151aae3c9da9c7cd14beaa9051bcd0 100644 (file)
--- a/src/net/file_windows.go
+++ b/src/net/file_windows.go
@@ -39,7 +39,7 @@ func dupFileSocket(f *os.File) (syscall.Handle, error) {
        err = sc.Control(func(fd uintptr) {
                h, syserr = dupSocket(syscall.Handle(fd))
        })
-       if err != nil {
+       if err == nil {
                err = syserr
        }
        if err != nil {