It isn't used by the code in current conditions but for safety it seems
sensible to at least not crash on such input.
Extended unit test 1395 to verify this too as well as a plain "/" input.
RFC3986 details how a path part passed in as part of a URI should be
"cleaned" from dot sequences before getting used. The described
algorithm is now implemented in lib/dotdot.c with the accompanied test
case in test 1395.
Bug: http://curl.haxx.se/bug/view.cgi?id=1200
Reported-by: Alex Vinnik