RFC 3986 section 5.2.2 allows for strict and non-strict resolution:
-- A non-strict parser may ignore a scheme in the reference
-- if it is identical to the base URI's scheme.
The tests
- rdf/rdf11/rdf-turtle/IRI-resolution-01.ttl
- rdf/rdf11/rdf-turtle/IRI-resolution-02.ttl
are affected because they have a test for resolving http:g against an http base.
There are two correct answers: if http: is ignored, the result is the same as resolving <g> (non-strict) otherwise it is <http:g> (strict - scheme already present).
if ((not strict) and (R.scheme == Base.scheme)) then
undefine(R.scheme);
endif;
if defined(R.scheme) then
T.scheme = R.scheme;
T.authority = R.authority;
T.path = remove_dot_segments(R.path);
T.query = R.query;
. . .
IRI-resolution-02 has:
@base <http://a/bb/ccc/d/>.
...
<urn:ex:s044> <urn:ex:p> <g>.
...
<urn:ex:s084> <urn:ex:p> <http:g>.
IRI-resolution-01 has a base of <http://a/bb/ccc/d;p?q>.