SPARQL 1.0: cover "GRAPH ?g {}" case

It should list all named graphs.
We did not have any test of GRAPH with an empty BGP.

Author: Tpt

sparql/sparql10/graph/graph-empty.rq

@@ -0,0 +1 @@
+SELECT * { GRAPH ?g {} }

sparql/sparql10/graph/graph-empty.ttl

@@ -0,0 +1,13 @@
+@prefix rs:      <http://www.w3.org/2001/sw/DataAccess/tests/result-set#> .
+@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+
+[]    rdf:type      rs:ResultSet ;
+      rs:resultVariable  "g" ;
+      rs:solution   [ rs:binding    [ rs:value      <data-g1.ttl> ;
+                                      rs:variable   "g"
+                                    ]
+                    ] ;
+      rs:solution   [ rs:binding    [ rs:value      <data-g2.ttl> ;
+                                      rs:variable   "g"
+                                    ]
+                    ] .

sparql/sparql10/graph/manifest.ttl

@@ -21,6 +21,7 @@
 	:dawg-graph-09
 	:dawg-graph-10b
 	:dawg-graph-11
+	:graph-empty
    ).
 
 :dawg-graph-01  rdf:type mf:QueryEvaluationTest ;
@@ -165,3 +166,14 @@
     mf:result  <graph-11.ttl> ;
     .
 
+:graph-empty  rdf:type mf:QueryEvaluationTest ;
+    mf:name "graph-empty" ;
+    rdfs:comment  "Graph with empty BGP: list all named graphs" ;
+    mf:action
+            [ qt:query        <graph-empty.rq> ;
+              qt:data         <data-g1.ttl> ;
+              qt:graphData    <data-g1.ttl> ;
+              qt:graphData    <data-g2.ttl> ;
+            ] ;
+    mf:result  <graph-empty.ttl> ;
+    .