Description:
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The ord($x) function (see http://www.php.net/function.ord) returns zero for the empty string or anything that can be silently converted to the empty string (NULL, TRUE). Surprisingly, ord($x) also returns 0 if an object is passed, although echo new stdClass() raises E_RECOVERABLE_ERROR: Object of class stdClass could not be converted to string.

Either the documentation should state this, or the engine should raise an error, just like it already does when $x is array or resource.

I run into this issue while reading the value of a byte read from a file: ord(fread($f,1)) returned 0 on EOF causing a infinite loop. An error would have helped detecting this bug early.

Test script:
---------------
// unexpected:
echo "ord(false): "; var_dump(ord(false)); // int(0) (!)
echo "ord(null): "; var_dump(ord(null)); // int(0) (!)
echo "ord(''): "; var_dump(ord('')); // int(0) (!)
echo "ord(new stdClass()): "; var_dump(new stdClass()); // int(0) (!)

// more or less expected:
echo "ord(true): "; var_dump(ord(true)); // int(49)
echo "ord(123): "; var_dump(ord(123)); // int(49)
echo "ord(0): "; var_dump(ord(0)); // int(48)
echo "ord(-1): "; var_dump(ord(-1)); // int(45)
echo "ord(3.14): "; var_dump(ord(3.14)); // int(51)
echo "ord(0.0): "; var_dump(ord(0.0)); // int(48)
echo "ord(-1.0): "; var_dump(ord(-1.0)); // int(45)
//echo "ord(array()): "; var_dump(ord(array())); // E_WARNING: ord() expects parameter 1 to be string, array given
//echo "ord(array(1,2,3)): "; var_dump(ord(array(1,2,3))); // E_WARNING: ord() expects parameter 1 to be string, array given
//echo "ord(fopen(__FILE__, 'r')): "; var_dump(ord(fopen(__FILE__, 'r'))); // E_WARNING: ord() expects parameter 1 to be string, resource given



Expected result:
----------------
// possible alternative:
echo "ord(false): "; var_dump(ord(false)); // E_WARNING: empty string in ord()
echo "ord(null): "; var_dump(ord(null)); // E_WARNING: empty string in ord()
echo "ord(''): "; var_dump(ord('')); //  E_WARNING: empty string in ord()
echo "ord(new stdClass()): "; var_dump(new stdClass()); // E_RECOVERABLE_ERROR: Object of class stdClass could not be converted to string

// more or less expected:
...