var s = "aaaaaaaaaaaaaaaaaa111aaaa";
var latin1Rope1 = "foo" + s;
var latin1Rope2 = "bar" + latin1Rope1;
var twoByteRope = "\u1200--" + latin1Rope1;

// Flatten twoByteRope.
assertEq(twoByteRope.lastIndexOf("11"), 25);

// latin1Rope1 is now a TwoByte dependent string.
assertEq(isLatin1(latin1Rope1), false);
assertEq(latin1Rope1, "fooaaaaaaaaaaaaaaaaaa111aaaa");

// latin1Rope2 should still be Latin1, but now has a
// TwoByte descendent (latin1Rope1).
if (isLatin1(s))
    assertEq(isLatin1(latin1Rope2), true);

// Flatten latin1Rope2.
assertEq(latin1Rope2.lastIndexOf("11"), 25);
assertEq(latin1Rope2, "barfooaaaaaaaaaaaaaaaaaa111aaaa");