HostFiles and HostFiles64 amended to follow symlinks on File.Register calls.

So, if the name passed to Register denotes a symlink-file, then this symlink is resolved in POSIXcompliant manner until a regular file is reached.

If the last component of the resulting normalized (canonicalized) name does not exist, it is created. (That is, if the link exists but points to a nonexistent file in a valid directory)

If the link is broken, Register returns an error.

Implementation notes:

canonicalize_file_name() Libc function is used to normalize (canonicalize) the filename passed to .Register. If the name cannot be normalized because the target file is not found, then .Register treats this as registering a new file, and the new file is open by open() Libc function. Otherwise, if the name cannot be normalized for whatever other reason, Register returns and error and does not attempt to actually perform any file operations.
If the name is successfully normalized, .Register treats this as before the amendment.