core: return the index of the block that failed when inserting a chain

1 files changed, 5 insertions, 3 deletions

diff --git a/core/chain_manager.go b/core/chain_manager.go
index 32ad4a2ba..253228bfd 100644
--- a/core/chain_manager.go
+++ b/core/chain_manager.go
@@ -497,7 +497,9 @@ func (self *ChainManager) procFutureBlocks() {
 	self.InsertChain(blocks)
 }
 
-func (self *ChainManager) InsertChain(chain types.Blocks) error {
+// InsertChain will attempt to insert the given chain in to the canonical chain or, otherwise, create a fork. It an error is returned
+// it will return the index number of the failing block as well an error describing what went wrong (for possible errors see core/errors.go).
+func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 	// A queued approach to delivering events. This is generally faster than direct delivery and requires much less mutex acquiring.
 	var (
 		queue      = make([]interface{}, len(chain))
@@ -540,7 +542,7 @@ func (self *ChainManager) InsertChain(chain types.Blocks) error {
 			glog.V(logger.Error).Infoln(err)
 			glog.V(logger.Debug).Infoln(block)
 
-			return err
+			return i, err
 		}
 
 		block.Td = new(big.Int).Set(CalculateTD(block, self.GetBlock(block.ParentHash())))
@@ -613,7 +615,7 @@ func (self *ChainManager) InsertChain(chain types.Blocks) error {
 
 	go self.eventMux.Post(queueEvent)
 
-	return nil
+	return 0, nil
 }
 
 // diff takes two blocks, an old chain and a new chain and will reconstruct the blocks and inserts them