--negotiate does not work without username/password, bug report #1004841

docs/KNOWN_BUGS

@@ -3,6 +3,11 @@ join in and help us correct one or more of these! Also be sure to check the
 changelog of the current development status, as one or more of these problems
 may have been fixed since this was written!
 
+* To get HTTP Negotiate authentication to work fine, you need to provide a
+  (fake) user name (this concerns both curl and the lib) because the code
+  wrongly only considers authentication if there's a user name provided.
+  Bug report #1004841.
+
 * If you use a very large amount of file descriptors (more than FD_SETSIZE)
   and then use libcurl, it might crash on its use of select() which then
   stores data out of bounds. Bug report #948950.