src/third_party/v8/test/mjsunit/regress/regress-386.js

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// Test for http://code.google.com/p/v8/issues/detail?id=386
// This test creates enough properties in A so that adding i as
// a constant function, in the first call to the constructor, leaves
// the object's map in the fast case and adds a constant function map
// transition.
// Adding i in the second call to the constructor creates a real property,
// and simultaneously converts the object from fast case to slow case
// and changes i from a map transition to a real property.  There was
// a flaw in the code that handled this combination of events.

function A() {
 for (var i = 0; i < 13; i++) {
   this['a' + i] = i;
 }
 this.i = function(){};
};

new A();
new A();