fixed bug in Extensible Store

Author: hmottestad

core/sail/extensible-store/src/main/java/org/eclipse/rdf4j/sail/extensiblestore/ReadCommittedWrapper.java

@@ -50,14 +50,18 @@ class ReadCommittedWrapper implements DataStructureInterface {
 
 	@Override
 	public void addStatement(ExtensibleStatement statement) {
-		internalAdded.put(statement, statement);
-		internalRemoved.remove(statement);
-
+		ExtensibleStatement put = internalAdded.put(statement, statement);
+		if (put == null) {
+			internalRemoved.remove(statement);
+		}
 	}
 
 	@Override
 	public void removeStatement(ExtensibleStatement statement) {
-		internalRemoved.put(statement, statement);
+		ExtensibleStatement put = internalRemoved.put(statement, statement);
+		if (put == null) {
+			internalAdded.remove(statement);
+		}
 
 	}
 

testsuites/sail/src/main/java/org/eclipse/rdf4j/testsuite/sail/RDFNotifyingStoreTest.java

@@ -180,12 +180,13 @@ public void testUpdateQuery2() {
 					"INSERT {" + statement + "}" +
 					"WHERE {?a ?b ?c}").execute();
 
-			assertEquals(1, added.size());
-			assertEquals(1, removed.size());
+			assertEquals(added, removed, "Added (expected) is not the same as removed (actual)");
+
 			assertEquals(2, addedRaw.size());
 			assertEquals(2, removedRaw.size());
 
-			assertEquals(added, removed);
+			assertEquals(1, added.size());
+			assertEquals(1, removed.size());
 
 		}