1 files changed, 8 insertions, 1 deletions
diff --git a/src/os/exec/env_test.go b/src/os/exec/env_test.go
index 47b7c04705..43d14fb56d 100644
--- a/src/os/exec/env_test.go
+++ b/src/os/exec/env_test.go
@@ -12,6 +12,7 @@ import (
 func TestDedupEnv(t *testing.T) {
 	tests := []struct {
 		noCase  bool
+		nulOK   bool
 		in      []string
 		want    []string
 		wantErr bool
@@ -36,9 +37,15 @@ func TestDedupEnv(t *testing.T) {
 			want:    []string{"B=b"},
 			wantErr: true,
 		},
+		{
+			// Plan 9 needs to preserve environment variables with NUL (#56544).
+			nulOK: true,
+			in:    []string{"path=one\x00two"},
+			want:  []string{"path=one\x00two"},
+		},
 	}
 	for _, tt := range tests {
-		got, err := dedupEnvCase(tt.noCase, tt.in)
+		got, err := dedupEnvCase(tt.noCase, tt.nulOK, tt.in)
 		if !reflect.DeepEqual(got, tt.want) || (err != nil) != tt.wantErr {
 			t.Errorf("Dedup(%v, %q) = %q, %v; want %q, error:%v", tt.noCase, tt.in, got, err, tt.want, tt.wantErr)
 		}