Disabling JIT in Safari 6 to workaround severe Javascript JIT bugs

Question

We found a severe problem with the interpretation of our Javascript code that only occurs on iOS 5/Safari 6 (then current iPad release) that we think is due to critical bug in t

Answer 1

Actually, the FOR loop bug is still present in Safari on iOS 7.0.4 in iPhone 4 and iPad 2. The loop failing can be significantly simpler than the illustration above, and it rakes several passes through the code to hit. Changing to a WHILE loop allows proper execution.

Failing code:

function zf(num,digs) 
{ 
var out = ""; 
var n = Math.abs(num); 
for (digs;  digs>0||n>0; digs--)
{ 
    out = n%10 + out; 
    n = Math.floor(n/10); 
}  
return num<0?"-"+out:out; 
} 

Successful code:

function zf(num,digs) 
{ 
var out = ""; 
var n = Math.abs(num); 
do 
{ 
    out = n%10 + out; 
    n = Math.floor(n/10); 
} 
while (--digs>0||n>0) 
return num<0?"-"+out:out; 
}