sys, dialer: leave non-Windows code unchanged

Only the Windows listener and dialer take the unix:// scheme.

Assisted-by: OpenCode (claude-sonnet-5-5)
Signed-off-by: Eric Curtin <eric.curtin@docker.com>

pkg/dialer/dialer_unix.go

@@ -27,12 +27,8 @@ import (
 )
 
 // DialAddress returns the address with unix:// prepended to the
-// provided address. An address that already carries the scheme is
-// returned unchanged.
+// provided address
 func DialAddress(address string) string {
-	if strings.HasPrefix(address, "unix://") {
-		return address
-	}
 	return "unix://" + address
 }
 

pkg/dialer/dialer_unix_test.go

@@ -1,39 +0,0 @@
-//go:build !windows
-
-/*
-   Copyright The containerd Authors.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-package dialer
-
-import "testing"
-
-func TestDialAddressScheme(t *testing.T) {
-	testcases := []struct {
-		name    string
-		address string
-		want    string
-	}{
-		{name: "bare path gets unix", address: "/run/containerd/containerd.sock", want: "unix:///run/containerd/containerd.sock"},
-		{name: "unix scheme idempotent", address: "unix:///run/containerd/containerd.sock", want: "unix:///run/containerd/containerd.sock"},
-	}
-	for _, tc := range testcases {
-		t.Run(tc.name, func(t *testing.T) {
-			if got := DialAddress(tc.address); got != tc.want {
-				t.Errorf("DialAddress(%q) = %q, want %q", tc.address, got, tc.want)
-			}
-		})
-	}
-}

pkg/sys/socket_test.go

@@ -20,6 +20,7 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 	"time"
 
@@ -73,7 +74,12 @@ func checkAccept(t *testing.T, l net.Listener, dial func() (net.Conn, error)) {
 }
 
 func TestGetLocalListenerUnixSocket(t *testing.T) {
-	for _, prefix := range []string{"", "unix://"} {
+	prefixes := []string{""}
+	if runtime.GOOS == "windows" {
+		// Only the Windows listener takes the scheme.
+		prefixes = append(prefixes, "unix://")
+	}
+	for _, prefix := range prefixes {
 		t.Run("prefix="+prefix, func(t *testing.T) {
 			sockPath := filepath.Join(shortTempDir(t), "test.sock")
 

pkg/sys/socket_unix.go

@@ -23,7 +23,6 @@ import (
 	"net"
 	"os"
 	"path/filepath"
-	"strings"
 
 	"golang.org/x/sys/unix"
 )
@@ -43,11 +42,8 @@ func CreateUnixSocket(path string) (net.Listener, error) {
 	return net.Listen("unix", path)
 }
 
-// GetLocalListener returns a listener out of a unix socket. The path may
-// carry a "unix://" prefix, as in dialer.DialAddress.
+// GetLocalListener returns a listener out of a unix socket.
 func GetLocalListener(path string, uid, gid int) (net.Listener, error) {
-	path = strings.TrimPrefix(path, "unix://")
-
 	// Ensure parent directory is created
 	if err := mkdirAs(filepath.Dir(path), uid, gid); err != nil {
 		return nil, err