I just added version 1.5.0 to SourceForge.net. This newer version includes a new function that one can use to convert a URI to lowercase. This is important to call tld() because the URI is going to be compared to top level domain names that are all in lowercase.
The new function is called tld_domain_to_lowercase(). It takes a string as input and returns a copy in lowercase. The function understands encoded URIs and UTF-8 as expected by the standard.
The project also includes a new test to make sure I get all the versions bumped each time I do a new update.
P.S. I published 1.5.1 today because I noticed that I did not add the new tld_domain_to_lowercase.c file to the dev/libtld-only-CMakeLists.txt and thus if you are one of the people using that file to build the library, it would not be available in the library.