},
		{
			name:    "IPv4 offset 0 not nibble boundary",
			address: netip.MustParseAddr("192.168.0.11"),
			offset:  0,
			want:    netip.MustParseAddr("192.168.0.11"),
		},
		{
			name:    "IPv4 offset 1",
			address: netip.MustParseAddr("192.168.0.0"),
			offset:  1,
			want:    netip.MustParseAddr("192.168.0.1"),
		},
		{
			name:    "IPv4 offset 1 not nibble boundary",

		Dir:  cwd,
		Env: []string{
			"SCRIPT_FILENAME=" + cgifile,
			"REQUEST_URI=/foo/bar",
			"PATH=/wibble"},
	}
	expectedMap := map[string]string{
		"cwd":                 cwd,
		"env-SCRIPT_FILENAME": cgifile,
		"env-REQUEST_URI":     "/foo/bar",
		"env-PATH":            "/wibble",
	}
	runCgiTest(t, h, "GET /test.cgi HTTP/1.0\nHost: example.com\n\n", expectedMap)
}

	locb = 0b10000000
	hicb = 0b10111111

	// These names of these constants are chosen to give nice alignment in the
	// table below. The first nibble is an index into acceptRanges or F for
	// special one-byte cases. The second nibble is the Rune length or the
	// Status for the special one-byte case.
	xx = 0xF1 // invalid: size 1
	as = 0xF0 // ASCII: size 1
	s1 = 0x02 // accept 0, size 2

		intermediates: [][]constraintsSpec{
			{
				{},
			},
		},
		leaf: leafSpec{
			sans: []string{
				"uri:http://example.com/bar",
				"uri:http://example.com:8080/",
				"uri:https://example.com/wibble#bar",
			},
		},
	},

	// #51: URIs with IPs are rejected
	{
		roots: []constraintsSpec{
			{
				ok: []string{"uri:example.com"},
			},
		},
		intermediates: [][]constraintsSpec{