update TestForkExec with invalid testcase

src/os/exec_linux.go

@@ -45,6 +45,10 @@ func (p *Process) release() error {
 // * No parent-child communication via pipes (TODO)
 // * No waiting for crashes child processes to prohibit zombie process accumulation / Wait status checking (TODO)
 func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error) {
+	if argv == nil {
+		return 0, errors.New("exec: no argv")
+	}
+
 	if len(argv) == 0 {
 		return 0, errors.New("exec: no argv")
 	}

src/os/exec_linux_test.go

@@ -18,15 +18,22 @@ func TestForkExec(t *testing.T) {
 		return
 	}
 
-	proc, err := StartProcess("/bin/echo", []string{"hello", "world"}, &ProcAttr{})
+	proc, err := StartProcess("echo", []string{"/bin/echo", "hello", "world"}, &ProcAttr{})
 	if !errors.Is(err, nil) {
 		t.Fatalf("forkExec failed: %v", err)
-		return
 	}
 
 	if proc.Pid == 0 {
 		t.Fatalf("forkExec failed: new process has pid 0")
 	}
-
 	t.Logf("forkExec succeeded: new process has pid %d", proc)
+
+	proc, err = StartProcess("invalid", []string{"/bin/nonexistent"}, &ProcAttr{})
+	if errors.Is(err, nil) {
+		t.Fatalf("wanted err, got nil")
+	}
+
+	if proc.Pid != 0 {
+		t.Fatalf("wanted 0, got %v", proc.Pid)
+	}
 }