tapgarden: stop caretaker on confirmation err

In this commit, we update the TX confirmation handling logic to stop the
caretaker if confirmation registration fails. At that point, the
caretaker cannot successfully receive a confirmation for the broadcast
batch, so it should shut down to allow caretaker restart for the same
batch. Note that the planter will not actually delete the stopped
caretaker, as the error is not sent on BroadcastErrChan.

Author: jharveyb

tapgarden/caretaker.go

@@ -879,13 +879,14 @@ func (b *BatchCaretaker) stateStep(currentState BatchState) (BatchState, error)
 			for !confRecv {
 				select {
 				case confEvent = <-confNtfn.Confirmed:
-					log.Debugf("Got chain confirmation: %v",
-						confEvent.Tx.TxHash())
 					confRecv = true
 
 				case err := <-errChan:
-					b.cfg.ErrChan <- fmt.Errorf("error "+
-						"getting confirmation: %w", err)
+					confErr := fmt.Errorf("error getting "+
+						"confirmation: %w", err)
+					log.Info(confErr)
+					b.cfg.ErrChan <- confErr
+
 					return
 
 				case <-confCtx.Done():
@@ -911,11 +912,19 @@ func (b *BatchCaretaker) stateStep(currentState BatchState) (BatchState, error)
 			}
 
 			if confEvent == nil {
-				b.cfg.ErrChan <- fmt.Errorf("got empty " +
+				confErr := fmt.Errorf("got empty " +
 					"confirmation event in batch")
+				log.Info(confErr)
+				b.cfg.ErrChan <- confErr
+
 				return
 			}
 
+			if confEvent.Tx != nil {
+				log.Debugf("Got chain confirmation: %v",
+					confEvent.Tx.TxHash())
+			}
+
 			for {
 				select {
 				case b.confEvent <- confEvent: