Allow identical batches to be sent to multiple contacts.

components/net/sf/briar/db/JdbcDatabase.java

@@ -127,7 +127,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		+ " (batchId HASH NOT NULL,"
 		+ " contactId INT NOT NULL,"
 		+ " messageId HASH NOT NULL,"
-		+ " PRIMARY KEY (batchId, messageId),"
+		+ " PRIMARY KEY (batchId, contactId, messageId),"
 		+ " FOREIGN KEY (batchId, contactId)"
 		+ " REFERENCES outstandingBatches (batchId, contactId)"
 		+ " ON DELETE CASCADE,"

test/net/sf/briar/db/H2DatabaseTest.java

@@ -461,7 +461,6 @@ public class H2DatabaseTest extends TestCase {
 		assertEquals(contactId, db.addContact(txn, transports, secret));
 		db.addBatchToAck(txn, contactId, batchId);
 		db.addBatchToAck(txn, contactId, batchId);
-		db.commitTransaction(txn);
 
 		// The batch ID should only be returned once
 		Collection<BatchId> acks = db.getBatchesToAck(txn, contactId);
@@ -479,6 +478,54 @@ public class H2DatabaseTest extends TestCase {
 		db.close();
 	}
 
+	@Test
+	public void testSameBatchCannotBeSentTwice() throws DbException {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add a contact, subscribe to a group and store a message
+		assertEquals(contactId, db.addContact(txn, transports, secret));
+		db.addSubscription(txn, group);
+		db.addMessage(txn, message);
+
+		// Add an outstanding batch
+		db.addOutstandingBatch(txn, contactId, batchId,
+				Collections.singleton(messageId));
+
+		// It should not be possible to add the same outstanding batch again
+		try {
+			db.addOutstandingBatch(txn, contactId, batchId,
+					Collections.singleton(messageId));
+			fail();
+		} catch(DbException expected) {}
+
+		db.abortTransaction(txn);
+		db.close();
+	}
+
+	@Test
+	public void testSameBatchCanBeSentToDifferentContacts() throws DbException {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add two contacts, subscribe to a group and store a message
+		assertEquals(contactId, db.addContact(txn, transports, secret));
+		ContactId contactId1 = db.addContact(txn, transports, secret);
+		db.addSubscription(txn, group);
+		db.addMessage(txn, message);
+
+		// Add an outstanding batch for the first contact
+		db.addOutstandingBatch(txn, contactId, batchId,
+				Collections.singleton(messageId));
+
+		// Add the same outstanding batch for the second contact
+		db.addOutstandingBatch(txn, contactId1, batchId,
+				Collections.singleton(messageId));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	@Test
 	public void testRemoveAckedBatch() throws DbException {
 		Database<Connection> db = open(false);