Merge PR #4895: Lite Client Query Height Fix

.pending/bugfixes/_4891-Disable-queryi

@@ -0,0 +1 @@
+#4891 Disable querying with proofs enabled when the query height <= 1.

client/context/query.go

@@ -74,13 +74,19 @@ func (ctx CLIContext) GetFromName() string {
 
 // query performs a query to a Tendermint node with the provided store name
 // and path. It returns the result and height of the query upon success
-// or an error if the query fails.
+// or an error if the query fails. In addition, it will verify the returned
+// proof if TrustNode is disabled. If proof verification fails or the query
+// height is invalid, an error will be returned.
 func (ctx CLIContext) query(path string, key cmn.HexBytes) (res []byte, height int64, err error) {
 	node, err := ctx.GetNode()
 	if err != nil {
 		return res, height, err
 	}
 
+	if ctx.Height <= 1 && !ctx.TrustNode {
+		return res, height, errors.New("cannot query with proof when height <= 1; please provide a valid height")
+	}
+
 	opts := rpcclient.ABCIQueryOptions{
 		Height: ctx.Height,
 		Prove:  !ctx.TrustNode,

store/rootmulti/store.go

@@ -402,7 +402,7 @@ func (rs *Store) Query(req abci.RequestQuery) abci.ResponseQuery {
 	}
 
 	if res.Proof == nil || len(res.Proof.Ops) == 0 {
-		return errors.ErrInternal("substore proof was nil/empty when it should never be").QueryResult()
+		return errors.ErrInternal("proof is unexpectedly empty; ensure height has not been pruned").QueryResult()
 	}
 
 	commitInfo, errMsg := getCommitInfo(rs.db, res.Height)