setJitCompilerOption('ion.forceinlineCaches', 1); function protoChange() { var o = {0: 0, 1: 0, 0x10000: 0, 0x20000: 0}; var tests = [1, 0, 0x10000, 0x20000]; function result_map(key, i) { if (i > 5 && key == 0x20000) return undefined; return 0; } for (var i = 0; i < 10; i++) { for (var key of tests) { assertEq(o[key], result_map(key, i)); } if (i == 5) { delete o[0x20000]; } } } for (var i = 0; i < 10; i++) { protoChange(); }