Description:
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array_combine issues a warning when empty arrays are passed as arguments, I submit that empty arrays should be valid input for this function, and the result should also be an empty array (rather than FALSE and a warning).

On top of that, the warning is non-sensical, as it states that  "Both parameters should have number of elements at least 0"

Reproduce code:
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$a = array();
$b = array();
$c = array_combine( $a, $b );
var_dump( $c );

Expected result:
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array(0) { }

Actual result:
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Warning: array_combine() [function.array-combine]: Both parameters should have number of elements at least 0 in /var/www/vhosts/.../test.php on line 4
bool(false)