1 files changed, 73 insertions, 0 deletions
diff --git a/src/syscall/exec_windows_test.go b/src/syscall/exec_windows_test.go
index eda1d36877..fb2c767c35 100644
--- a/src/syscall/exec_windows_test.go
+++ b/src/syscall/exec_windows_test.go
@@ -5,8 +5,14 @@
 package syscall_test
 
 import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"syscall"
 	"testing"
+	"time"
 )
 
 func TestEscapeArg(t *testing.T) {
@@ -41,3 +47,70 @@ func TestEscapeArg(t *testing.T) {
 		}
 	}
 }
+
+func TestChangingProcessParent(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") == "parent" {
+		// in parent process
+
+		// Parent does nothign. It is just used as a parent of a child process.
+		time.Sleep(time.Minute)
+		os.Exit(0)
+	}
+
+	if os.Getenv("GO_WANT_HELPER_PROCESS") == "child" {
+		// in child process
+		dumpPath := os.Getenv("GO_WANT_HELPER_PROCESS_FILE")
+		if dumpPath == "" {
+			fmt.Fprintf(os.Stderr, "Dump file path cannot be blank.")
+			os.Exit(1)
+		}
+		err := os.WriteFile(dumpPath, []byte(fmt.Sprintf("%d", os.Getppid())), 0644)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error writing dump file: %v", err)
+			os.Exit(2)
+		}
+		os.Exit(0)
+	}
+
+	// run parent process
+
+	parent := exec.Command(os.Args[0], "-test.run=TestChangingProcessParent")
+	parent.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=parent")
+	err := parent.Start()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		parent.Process.Kill()
+		parent.Wait()
+	}()
+
+	// run child process
+
+	const _PROCESS_CREATE_PROCESS = 0x0080
+	const _PROCESS_DUP_HANDLE = 0x0040
+	childDumpPath := filepath.Join(t.TempDir(), "ppid.txt")
+	ph, err := syscall.OpenProcess(_PROCESS_CREATE_PROCESS|_PROCESS_DUP_HANDLE|syscall.PROCESS_QUERY_INFORMATION,
+		false, uint32(parent.Process.Pid))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer syscall.CloseHandle(ph)
+
+	child := exec.Command(os.Args[0], "-test.run=TestChangingProcessParent")
+	child.Env = append(os.Environ(),
+		"GO_WANT_HELPER_PROCESS=child",
+		"GO_WANT_HELPER_PROCESS_FILE="+childDumpPath)
+	child.SysProcAttr = &syscall.SysProcAttr{ParentProcess: ph}
+	childOutput, err := child.CombinedOutput()
+	if err != nil {
+		t.Errorf("child failed: %v: %v", err, string(childOutput))
+	}
+	childOutput, err = ioutil.ReadFile(childDumpPath)
+	if err != nil {
+		t.Fatalf("reading child output failed: %v", err)
+	}
+	if got, want := string(childOutput), fmt.Sprintf("%d", parent.Process.Pid); got != want {
+		t.Fatalf("child output: want %q, got %q", want, got)
+	}
+}