It's not clear to me if dropping support for this functionality was intentional.

Chain of events:

- #21689 removed test coverage due to a misunderstanding due, I believe, to this functionality being generally supported by all platforms except macOS which does not and returns a different format
- #21756 removed support and caused this regression
- #21690 restores the test coverage that would have caught this regression

Currently, neither the test coverage before #21689 nor the coverage restored by #21690 pass since the merge of #21756.

BOOST_REQUIRE(addr.SetSpecial("6hzph5hv6337r6p2.onion"));
    BOOST_REQUIRE(addr.IsValid());
    BOOST_REQUIRE(addr.IsTor());
    BOOST_CHECK(!addr.IsI2P());
    BOOST_CHECK(!addr.IsBindAny());
    BOOST_CHECK(addr.IsAddrV1Compatible());
    BOOST_CHECK_EQUAL(addr.ToString(), "6hzph5hv6337r6p2.onion");
    
    const char* torv3_addr = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion";
    BOOST_REQUIRE(addr.SetSpecial(torv3_addr));
    BOOST_REQUIRE(addr.IsValid());
    BOOST_REQUIRE(addr.IsTor());
    BOOST_CHECK(!addr.IsI2P());
    BOOST_CHECK(!addr.IsBindAny());
    BOOST_CHECK(!addr.IsAddrV1Compatible());
    BOOST_CHECK_EQUAL(addr.ToString(), torv3_addr);
    
    BOOST_CHECK(!addr.SetSpecial("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscsad.onion"));
    
    BOOST_CHECK(!addr.SetSpecial("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscrye.onion"));
    
    BOOST_CHECK(!addr.SetSpecial(std::string{
        "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd\0wtf.onion", 66}));
    
    BOOST_CHECK(!addr.SetSpecial(std::string{"mfrggzak.onion"}));
    
    BOOST_CHECK(!addr.SetSpecial(std::string{"mf*g zak.onion"}));
    
    const char* i2p_addr = "UDHDrtrcetjm5sxzskjyr5ztpeszydbh4dpl3pl4utgqqw2v4jna.b32.I2P";
    BOOST_REQUIRE(addr.SetSpecial(i2p_addr));