michael@0: function testInt32ToId()
michael@0: {
michael@0:   // Ensure that a property which is a negative integer that does not fit in a
michael@0:   // jsval is properly detected by the 'in' operator.
michael@0:   var obj = { "-1073741828": 17 };
michael@0:   var index = -1073741819;
michael@0:   var a = [];
michael@0:   for (var i = 0; i < 10; i++)
michael@0:   {
michael@0:     a.push(index in obj);
michael@0:     index--;
michael@0:   }
michael@0: 
michael@0:   // Ensure that a property which is a negative integer that does not fit in a
michael@0:   // jsval is properly *not* detected by the 'in' operator.  In this case
michael@0:   // wrongly applying INT_TO_JSID to -2147483648 will shift off the sign bit
michael@0:   // (the only bit set in that number) and bitwise-or that value with 1,
michael@0:   // producing jsid(1) -- which actually represents "0", not "-2147483648".
michael@0:   // Thus 'in' will report a "-2147483648" property when none exists, because
michael@0:   // it thinks the request was really whether the object had property "0".
michael@0:   var obj2 = { 0: 17 };
michael@0:   var b = [];
michael@0:   var index = -(1 << 28);
michael@0:   for (var i = 0; i < 10; i++)
michael@0:   {
michael@0:     b.push(index in obj2);
michael@0:     index = index - (1 << 28);
michael@0:   }
michael@0: 
michael@0:   return a.join(",") + b.join(",");
michael@0: }
michael@0: 
michael@0: assertEq(testInt32ToId(),   
michael@0: 	 "false,false,false,false,false,false,false,false,false,true" +
michael@0: 	 "false,false,false,false,false,false,false,false,false,false");