Different meanings in AltTagList.get_value_by_key() functions?

[ltog]

The meaning in lines 44 and 52 is not the same?

osmi-addresses/osmi/AltTagList.hpp

Lines 44 to 52 in e572383

	if (m_list.find(key) == m_list.end()) {
	return std::string("");
	} else {
	return m_list.find(key)->second;
	}
	}
	std::string get_value_by_key(char* key) {
	if (!key) {

[ltog]

Using get_value_by_key(const char* key) leads to segfaults when querying non-existing keys.