if err != nil {
		t.Errorf("read error: %v", err)
	}
	if n != 0 {
		t.Errorf("wrong count; got %d want 0", n)
	}
}

func TestUnreadByte(t *testing.T) {
	b := new(Buffer)

	// check at EOF
	if err := b.UnreadByte(); err == nil {
		t.Fatal("UnreadByte at EOF: got no error")
	}
	if _, err := b.ReadByte(); err == nil {
		t.Fatal("ReadByte at EOF: got no error")
	}

				if err != nil {
					if !test.wantErr {
						t.Errorf("%s: %v", path, err)
					}
					sawErr = true
					return nil
				}
				files = append(files, path)
				return nil
			})
			if err != nil {
				t.Errorf("fs.WalkDir error: %v", err)
			}
			if test.wantErr && !sawErr {
				t.Error("succeeded but want error")

	defer func() {
		if x := recover(); x != nil {
			t.Errorf("expected no panic; recovered %v", x)
		}
	}()

	testenv.MustHaveGoBuild(t)

	for _, context := range contexts {
		w := NewWalker(context, "testdata/src/issue64958")
		pkg, err := w.importFrom("p", "", 0)
		if err != nil {
			t.Errorf("expected no error importing; got %T", err)
		}
		w.export(pkg)
	}
}

				time.Sleep(time.Millisecond)
				continue
			}

			t.Error(err)
			return
		}
		cmds = append(cmds, cmd)
	}

	failures := 0
	for _, cmd := range cmds {
		err := cmd.Wait()
		if err == nil {
			continue
		}

		t.Errorf("syscall.Exec failed: %v\n%s", err, cmd.Stdout)
		failures++
	}

	if failures > 0 {

			parser.lineNum++
			if !parser.pseudo(test.pseudo, tokenize(test.operands)) {
				t.Fatalf("Wrong pseudo-instruction: %s", test.pseudo)
			}
			errorLine := buf.String()
			if test.expected != errorLine {
				t.Errorf("Unexpected error %q; expected %q", errorLine, test.expected)
			}
			buf.Reset()
		}
	}

			addr := obj.Addr{}
			parser.operand(&addr)
		})

		switch {
		case err == nil:
			t.Errorf("fail at %s: got no errors; expected %s\n", test.input, test.error)
		case !strings.Contains(err.Error(), test.error):
			t.Errorf("fail at %s: got %s; expected %s", test.input, err, test.error)
		}
	}
}

func testOperandParser(t *testing.T, parser *Parser, tests []operandTest) {
	for _, test := range tests {

		got := r.File[i]
		if got.Name != want.name {
			t.Errorf("got Name %s; want %s", got.Name, want.name)
		}
		if got.Method != want.method {
			t.Errorf("%s: got Method %#x; want %#x", want.name, got.Method, want.method)
		}
		if got.Flags != want.flags {
			t.Errorf("%s: got Flags %#x; want %#x", want.name, got.Flags, want.flags)
		}
		if got.CRC32 != want.crc32 {

		a := Repeat(tin, tt.count)
		if !Equal(a, tout) {
			t.Errorf("Repeat(%q, %d) = %q; want %q", tin, tt.count, a, tout)
			continue
		}
	}
}

func repeat(b []byte, count int) (err error) {
	defer func() {
		if r := recover(); r != nil {
			switch v := r.(type) {
			case error:
				err = v
			default:
				err = fmt.Errorf("%s", v)
			}
		}
	}()

	Repeat(b, count)

		if err == nil {
			if test.error != "" {
				t.Errorf("#%d: %q: expected error %q; got none", i, test.input, test.error)
			}
			continue
		}
		if !strings.Contains(err.Error(), test.error) {
			t.Errorf("#%d: expected error %q; got %q", i, test.error, err)
			continue
		}
	}
}

func runBadTest(i int, test badExprTest, t *testing.T) (err error) {

	vs := []struct {
		call           string
		fn             func() error
		filter, expect string
	}{
		{call: "Setegid(1)", fn: func() error { return syscall.Setegid(1) }, filter: "Gid:", expect: "\t0\t1\t0\t1"},
		{call: "Setegid(0)", fn: func() error { return syscall.Setegid(0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"},

		{call: "Seteuid(1)", fn: func() error { return syscall.Seteuid(1) }, filter: "Uid:", expect: "\t0\t1\t0\t1"},