fix: Fix broken pushes to tickets

The update of JGit broke pushes to tickets. The ReceiveCommand now
requires all three arguments, oldId, newId and name, to be not null.
The ticket code handling pushes to tickets left name and old id as
null in certain cases. This is fixed by always providing values.

src/main/java/com/gitblit/git/PatchsetCommand.java

 
 	public PatchsetCommand(String username, Patchset patchset) {
 		super(patchset.isFF() ? ObjectId.fromString(patchset.parent) : ObjectId.zeroId(),
-				ObjectId.fromString(patchset.tip), null);
+				ObjectId.fromString(patchset.tip), getPatchsetBranch(patchset.ticketId, patchset.number));
 		this.change = new Change(username);
 		this.change.patchset = patchset;
 	}

src/main/java/com/gitblit/git/PatchsetReceivePack.java

 
 			// assign new id
 			long ticketId = ticketService.assignNewId(repository);
+			patchset.ticketId = ticketId;
 
 			// create the patchset command
 			psCmd = new PatchsetCommand(user.username, patchset);
 		newPatchset.tip = tip;
 		newPatchset.base = mergeBase;
 		newPatchset.commits = totalCommits;
+		newPatchset.ticketId = ticket == null ? 0 : ticket.number;
 
 		Patchset currPatchset = ticket == null ? null : ticket.getCurrentPatchset();
 		if (currPatchset == null) {
 	}
 
 	private RefUpdate updateRef(String ref, ObjectId newId, PatchsetType type) {
-		ObjectId ticketRefId = ObjectId.zeroId();
+		ObjectId ticketRefId = null;
 		try {
 			ticketRefId = getRepository().resolve(ref);
-		} catch (Exception e) {
-			// ignore
-		}
+		} catch (Exception ignored) {}
 
 		try {
 			RefUpdate ru = getRepository().updateRef(ref,  false);
 				break;
 			}
 
-			ru.setExpectedOldObjectId(ticketRefId);
+			ru.setExpectedOldObjectId((ticketRefId == null) ? ObjectId.zeroId() : ticketRefId);
 			ru.setNewObjectId(newId);
 			RefUpdate.Result result = ru.update(getRevWalk());
 			if (result == RefUpdate.Result.LOCK_FAILURE) {
 					ru.getResult(), ru.getName()));
 			return;
 		}
-		ReceiveCommand cmd = new ReceiveCommand(ru.getOldObjectId(), ru.getNewObjectId(), ru.getName(), type);
+		ObjectId oldId = (ru.getOldObjectId() == null) ? ObjectId.zeroId() : ru.getOldObjectId();
+		ReceiveCommand cmd = new ReceiveCommand(oldId, ru.getNewObjectId(), ru.getName(), type);
 		RefLogUtils.updateRefLog(user, getRepository(), Arrays.asList(cmd));
 	}
 
 	public void sendAll() {
 		ticketNotifier.sendAll();
 	}
-}
+}

src/main/java/com/gitblit/models/TicketModel.java

 
 		private static final long serialVersionUID = 1L;
 
+		public long ticketId;
 		public int number;
 		public int rev;
 		public String tip;