What function-specific encoding has changed from PHP5.2 to PHP5.4

If there is a file stored in ISO-8859-1, and using the command

echo "test: ".htmlspecialchars("äöü");

The return will only be "test:".

This is because the standard encoding for htmlspecialchars has changed to UTF-8 in PHP5.4. You need to explicitly set the encoding:

echo "test: ".htmlspecialchars("äöü", ENT_COMPAT | ENT_HTML401, 'ISO-8859-1');

Are there any other functions in PHP5.4 that will no longer work properly if you don't set the encoding?