rpc: make getblock return orphan blocks with confirmation=-1

blockchain/chain.go

@@ -1394,8 +1394,8 @@ func (b *BlockChain) BlockAttributesByHash(hash *chainhash.Hash, prevHash *chain
 	attrs *BlockAttributes, best *BestState, err error) {
 	best = b.BestSnapshot()
 	node := b.index.LookupNode(hash)
-	if node == nil || !b.bestChain.Contains(node) {
-		str := fmt.Sprintf("block %s is not in the main chain", hash)
+	if node == nil {
+		str := fmt.Sprintf("block %s not found", hash)
 		return nil, best, errNotInMainChain(str)
 	}
 
@@ -1405,6 +1405,9 @@ func (b *BlockChain) BlockAttributesByHash(hash *chainhash.Hash, prevHash *chain
 		MedianTime:    node.CalcPastMedianTime(),
 		ChainWork:     node.workSum,
 	}
+	if !b.bestChain.Contains(node) {
+		attrs.Confirmations = -1
+	}
 
 	// Populate prev block hash if there is one.
 	if node.height > 0 {

rpcserver.go

@@ -1211,7 +1211,7 @@ func handleGetBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (i
 	if err != nil {
 		return nil, &btcjson.RPCError{
 			Code:    btcjson.ErrRPCBlockNotFound,
-			Message: "Block not found",
+			Message: "Block not found: " + err.Error(),
 		}
 	}
 	// If verbosity is 0, return the serialized block as a hex encoded string.