From 5031c82150106c0971fd32fc0eea9193340aec9b Mon Sep 17 00:00:00 2001
From: William Banfield <wbanfield@gmail.com>
Date: Thu, 19 May 2022 12:53:17 -0400
Subject: [PATCH] log on stripped extensions

---
 internal/blocksync/reactor.go |  4 +++-
 internal/consensus/state.go   | 10 +++++-----
 types/block.go                |  7 ++++++-
 types/vote.go                 |  7 +++++--
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/internal/blocksync/reactor.go b/internal/blocksync/reactor.go
index 210fde044..304d1b824 100644
--- a/internal/blocksync/reactor.go
+++ b/internal/blocksync/reactor.go
@@ -590,7 +590,9 @@ func (r *Reactor) poolRoutine(ctx context.Context, stateSynced bool, blockSyncCh
 				// if vote extensions were required at this height, ensure they exist.
 				err = extCommit.EnsureExtensions()
 			} else if err == nil && !state.ConsensusParams.ABCI.VoteExtensionsEnabled(extCommit.Height) {
-				extCommit.StripExtensions()
+				if stripped := extCommit.StripExtensions(); stripped {
+					r.logger.Error("commit included extension data but vote extensions are not enabled")
+				}
 			}
 			// If either of the checks failed we log the error and request for a new block
 			// at that height
diff --git a/internal/consensus/state.go b/internal/consensus/state.go
index b49226284..5dce21530 100644
--- a/internal/consensus/state.go
+++ b/internal/consensus/state.go
@@ -2407,16 +2407,15 @@ func (cs *State) addVote(
 			}
 		}
 	} else {
-		if vote.Extension != nil || vote.ExtensionSignature != nil {
-			cs.logger.Error("vote included extension data but vote extensions are not enabled", "peer", peerID)
-		}
 		// Vote extensions are not enabled on the network.
 		// strip the extension data from the vote in case any is present.
 		//
 		// TODO punish a peer if it sent a vote with an extension when the feature
 		// is disabled on the network.
 		// https://github.com/tendermint/tendermint/issues/8565
-		vote.StripExtensions()
+		if stripped := vote.StripExtension(); stripped {
+			cs.logger.Error("vote included extension data but vote extensions are not enabled", "peer", peerID)
+		}
 	}
 
 	height := cs.Height
@@ -2620,7 +2619,8 @@ func (cs *State) signAddVote(
 		return nil
 	}
 	if !cs.state.ConsensusParams.ABCI.VoteExtensionsEnabled(vote.Height) {
-		vote.StripExtensions()
+		// The signer will sign the extension, make sure to remove the data on the way out
+		vote.StripExtension()
 	}
 	cs.sendInternalMessage(ctx, msgInfo{&VoteMessage{vote}, "", tmtime.Now()})
 	cs.logger.Debug("signed and pushed vote", "height", cs.Height, "round", cs.Round, "vote", vote)
diff --git a/types/block.go b/types/block.go
index aedd90341..9267dcc98 100644
--- a/types/block.go
+++ b/types/block.go
@@ -1105,11 +1105,16 @@ func (ec *ExtendedCommit) EnsureExtensions() error {
 // StripExtensions removes all VoteExtension data from an ExtendedCommit. This
 // is useful when dealing with an ExendedCommit but vote extension data is
 // expected to be absent.
-func (ec *ExtendedCommit) StripExtensions() {
+func (ec *ExtendedCommit) StripExtensions() bool {
+	stripped := false
 	for idx := range ec.ExtendedSignatures {
+		if len(ec.ExtendedSignatures[idx].Extension) > 0 || len(ec.ExtendedSignatures[idx].ExtensionSignature) > 0 {
+			stripped = true
+		}
 		ec.ExtendedSignatures[idx].Extension = nil
 		ec.ExtendedSignatures[idx].ExtensionSignature = nil
 	}
+	return stripped
 }
 
 // ToCommit converts an ExtendedCommit to a Commit by removing all vote
diff --git a/types/vote.go b/types/vote.go
index 20f95df13..f7006b8cd 100644
--- a/types/vote.go
+++ b/types/vote.go
@@ -112,11 +112,14 @@ func (vote *Vote) CommitSig() CommitSig {
 	}
 }
 
-// StripExtensions removes any extension data from the vote. Useful if the
+// StripExtension removes any extension data from the vote. Useful if the
 // chain has not enabled vote extensions.
-func (vote *Vote) StripExtensions() {
+// Returns true if extension data was present before stripping and false otherwise.
+func (vote *Vote) StripExtension() bool {
+	stripped := len(vote.Extension) > 0 || len(vote.ExtensionSignature) > 0
 	vote.Extension = nil
 	vote.ExtensionSignature = nil
+	return stripped
 }
 
 // ExtendedCommitSig attempts to construct an ExtendedCommitSig from this vote.