1 files changed, 42 insertions, 0 deletions
diff --git a/src/os/exec/exec_windows_test.go b/src/os/exec/exec_windows_test.go
index 8e31e47190f..35ae0b0b8af 100644
--- a/src/os/exec/exec_windows_test.go
+++ b/src/os/exec/exec_windows_test.go
@@ -7,14 +7,31 @@
 package exec_test
 
 import (
+	"fmt"
 	"io"
 	"os"
 	"os/exec"
 	"strconv"
+	"strings"
 	"syscall"
 	"testing"
 )
 
+func init() {
+	registerHelperCommand("pipehandle", cmdPipeHandle)
+}
+
+func cmdPipeHandle(args ...string) {
+	handle, _ := strconv.ParseUint(args[0], 16, 64)
+	pipe := os.NewFile(uintptr(handle), "")
+	_, err := fmt.Fprint(pipe, args[1])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "writing to pipe failed: %v\n", err)
+		os.Exit(1)
+	}
+	pipe.Close()
+}
+
 func TestPipePassing(t *testing.T) {
 	r, w, err := os.Pipe()
 	if err != nil {
@@ -54,3 +71,28 @@ func TestNoInheritHandles(t *testing.T) {
 		t.Fatalf("got exit code %d; want 88", exitError.ExitCode())
 	}
 }
+
+// start a child process without the user code explicitly starting
+// with a copy of the parent's SYSTEMROOT.
+// (See issue 25210.)
+func TestChildCriticalEnv(t *testing.T) {
+	cmd := helperCommand(t, "echoenv", "SYSTEMROOT")
+
+	// Explicitly remove SYSTEMROOT from the command's environment.
+	var env []string
+	for _, kv := range cmd.Environ() {
+		k, _, ok := strings.Cut(kv, "=")
+		if !ok || !strings.EqualFold(k, "SYSTEMROOT") {
+			env = append(env, kv)
+		}
+	}
+	cmd.Env = env
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.TrimSpace(string(out)) == "" {
+		t.Error("no SYSTEMROOT found")
+	}
+}