Description:
------------
This string function fails on the "?" character (and other Latin-2 characters).

Test:

echo htmlentities("Ket?ua");

Returns: Ket?ua

Reproduce code:
---------------
Affected code:

$value = htmlentities($value);

preg_match_all("/&([^;]*);/", $value, $matches);
$parts = preg_split("/&|;/", $value, -1, PREG_SPLIT_NO_EMPTY);

foreach($parts as $part)
 $td->appendChild(
                    in_array($part, $matches[1])
                    ? $doc->createEntityReference($part)
                    : $doc->createTextNode($part)
                  );

Point of failure: the string "Ket?ua"

Expected result:
----------------
Character should be converted to Š (upper) / š (lower) per HTML spec (see special-1.ent listing).

Failing this, should it not be possible to create a TextNode containing this character when specifying a Latin-2 or Unicode charset?

Actual result:
--------------
Function returns the literal "?" character with no conversion.

It is not possible to create a TextNode containing this character using DOMDocument::createTextNode().

I have written a workaround which replaces the Lat-2 chars with their entity equivalents using str_replace(), but even so PHP still issues several warnings when sending output to the browser using DOMDocument::saveHTML():

Warning: output conversion failed due to conv error in O:\webs\mysqli\oop-multi-select-with-dom.php on line 172

Warning: Bytes: 0x92 0x49 0x76 0x6F in O:\webs\mysqli\oop-multi-select-with-dom.php on line 172

Warning: xmlOutputBufferWrite: encoder error in O:\webs\mysqli\oop-multi-select-with-dom.php on line 172

The correct entity (š) does get sent, but I have to suppress the error with an "@", which I don't like doing.