Created
July 26, 2013 16:57
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safari bug demo: tested in Safari Version 6.0.5 (8536.30.1)
bad(2,1) shall always return false. But in the buggy version of safari, it will return true from 75 to 95 times it's being called.
on the other hand very very similar version good, behave just as it should.
by warming up the bad function by about 100 times, it will almost behave correct…
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| <html> | |
| <head> | |
| <script type="text/javascript"> | |
| var append = function(text) { | |
| document.body.appendChild(document.createTextNode(text)); | |
| document.body.appendChild(document.createElement("br")); | |
| } | |
| bad = function(lhs, rhs) { | |
| var dist = (rhs - lhs) >>> 0; | |
| return dist < 256; | |
| } | |
| good = function(lhs, rhs) { | |
| return ((rhs - lhs) >>> 0) < 256; | |
| } | |
| var warm_up = function(c) { | |
| append("warm up starting..."); | |
| for(var i = 0; i < c; ++i) { | |
| bad(2, 1); | |
| } | |
| append("warm up done"); | |
| }; | |
| var bar = function() { | |
| //warm_up(100) | |
| for(var i = 0; i < 100; ++i) { | |
| var b = bad(2, 1); | |
| if(b) | |
| append("count=" + i + ", bad="+ b); | |
| var g = good(2, 1); | |
| if(g) | |
| append("count=" + i + ", good="+ g); | |
| } | |
| } | |
| setTimeout(bar, 0); | |
| </script> | |
| </head> | |
| </html> |
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