Description:
------------
json_encode converts integers to string in a different way than PHP's integer to string conversion (at least on win32). PHP appears to either handle unsigned values, or use more bits to encode integers, where as json_encode converts them to floats, causing rounding errors.


Reproduce code:
---------------
function show_eq($x,$y) {
  echo "$x ". ($x==$y ? "==" : "!=") ." $y\n";
}

$value = 0x7FFFFFFF; #2147483647;
show_eq("$value", json_encode($value));
$value++;
show_eq("$value", json_encode($value));


Expected result:
----------------
2147483647 == 2147483647
2147483648 == 2147483648

Which shows both functions handling unsigned (or "long") integers.

Or:

2147483647 == 2147483647
2147483650 == 2147483650

Which shows both functions converting to a float with less precision.


Actual result:
--------------
2147483647 == 2147483647
2147483648 != 2147483650

My code makes use of the "long" or "unsigned" (not sure what's actually happening) ability of PHP for unix timestamps, which I would dearly love to see stay.  The real issue is that the two functions behave in different ways, and should not.