Merge pull request #36719 from tbg/backport19.1/trunc-panic

backport-19.1: storage: prevent crash migrating from 19.1-beta into 19.1-rcX

pkg/settings/cluster/cockroach_versions.go

@@ -66,6 +66,7 @@ const (
 	VersionDirectImport
 	VersionSideloadedStorageNoReplicaID // see versionsSingleton for details
 	VersionPushTxnToInclusive
+	VersionSnapshotsWithoutLog
 	Version19_1
 
 	// Add new versions here (step one of two).
@@ -445,6 +446,10 @@ var versionsSingleton = keyedVersions([]keyedVersion{
 		Version: roachpb.Version{Major: 2, Minor: 1, Unstable: 10},
 	},
 	{
+		// VersionSnapshotsWithoutLog is https://github.com/cockroachdb/cockroach/pull/36714.
+		Key:     VersionSnapshotsWithoutLog,
+		Version: roachpb.Version{Major: 2, Minor: 1, Unstable: 11},
+	}, {
 		// Version19_1 is CockroachDB v19.1. It's used for all v19.1.x patch releases.
 		Key:     Version19_1,
 		Version: roachpb.Version{Major: 19, Minor: 1},

pkg/storage/replica_command.go

@@ -27,6 +27,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/keys"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/rpc/nodedialer"
+	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
 	"github.com/cockroachdb/cockroach/pkg/storage/engine"
 	"github.com/cockroachdb/cockroach/pkg/storage/storagebase"
 	"github.com/cockroachdb/cockroach/pkg/storage/storagepb"
@@ -903,7 +904,11 @@ func (r *Replica) sendSnapshot(
 		return errors.Wrap(err, "loading legacy truncated state")
 	}
 
-	if !usesReplicatedTruncatedState && snap.State.TruncatedState.Index < snap.State.RaftAppliedIndex {
+	canAvoidSendingLog := !usesReplicatedTruncatedState &&
+		snap.State.TruncatedState.Index < snap.State.RaftAppliedIndex &&
+		r.store.ClusterSettings().Version.IsActive(cluster.VersionSnapshotsWithoutLog)
+
+	if canAvoidSendingLog {
 		// If we're not using a legacy (replicated) truncated state, we avoid
 		// sending the (past) Raft log in the snapshot in the first place and
 		// send only those entries that are actually useful to the follower.