r := NewReader(&StringReader{data: []string{"日本語日本語日本語"}})
	if r.UnreadRune() == nil {
		t.Error("expected error on UnreadRune from fresh buffer")
	}
	_, _, err := r.ReadRune()
	if err != nil {
		t.Error("unexpected error on ReadRune (1):", err)
	}
	if err = r.UnreadRune(); err != nil {
		t.Error("unexpected error on UnreadRune (1):", err)
	}
	if r.UnreadRune() == nil {
		t.Error("expected error after UnreadRune (1)")
	}

			{
				Name:     "bar.txt",
				Content:  []byte("bar\n"),
				Modified: time.Date(1979, 11, 30, 0, 0, 0, 0, time.UTC),
				Mode:     0666,
			},
		},
	},
	// Tests that we verify (and accept valid) crc32s on files
	// with crc32s in their file header (not in data descriptors)
	{
		Name: "crc32-not-streamed.zip",
		File: []ZipTestFile{
			{
				Name:     "foo.txt",
				Content:  []byte("foo\n"),

		// Copy position information from old expr into new expr,
		// in case expression being replaced is first on line.
		// See golang.org/issue/6563.
		pos := (*r.Expr).Pos()
		if x, ok := expr.(*ast.Ident); ok {
			expr = &ast.Ident{NamePos: pos, Name: x.Name}
		}

		// Change AST, because some later processing depends on it,
		// and also because -godefs mode still prints the AST.
		old := *r.Expr
		*r.Expr = expr

	// Hex constant 0xFFFFFFFF80000001
	MOVD $-2147483647, R5           // 3ca0800060a50001 or 0603800038a00001
	// Hex constant 0xFFFFFFFE00000002 (load of constant on < power10, pli on >= power10
	MOVD $-8589934590, R5           // 3ca00000e8a50000 or 0602000038a00002

	// For backwards compatibility, MOVW $const,Rx and MOVWZ $const,Rx assemble identically
	// and accept the same constants.

	{"a.RegExp*", ".(|)*+?^$[]", 8},
	{dots + dots + dots, " ", -1},
	{"012abcba210", "\xffb", 6},
	{"012\x80bcb\x80210", "\xffb", 7},
	{"0123456\xcf\x80abc", "\xcfb\x80", 10},
}

// Execute f on each test case.  funcName should be the name of f; it's used
// in failure reports.
func runIndexTests(t *testing.T, f func(s, sep []byte) int, funcName string, testCases []BinOpTest) {
	for _, test := range testCases {