When converting ASCII smileys using asciiToShortname, asciiToShortnameCallback is called. This function executes array_flip(array_reverse($ruleset->getShortcodeReplace())); that always results in an empty array, replacing ASCII smileys with empty strings.
Also, function should return shortnames for smileys and not their unicode equivalents, therefore only $ascii_replace is needed.
When converting ASCII smileys using asciiToShortname, asciiToShortnameCallback is called. This function executes array_flip(array_reverse($ruleset->getShortcodeReplace())); that always results in an empty array, replacing ASCII smileys with empty strings. Also, function should return shortnames for smileys and not their unicode equivalents, therefore only $ascii_replace is needed.