From 73da5ee5d06b5f62c186b31ce37f7669edc8bbf2 Mon Sep 17 00:00:00 2001
From: Ava Howell <ava@avahowell.me>
Date: Tue, 4 Jun 2024 19:53:24 -0700
Subject: [PATCH] fix client state: disallow empty chain id

---
 crates/ibc-types-lightclients-tendermint/src/client_state.rs | 4 ++++
 crates/ibc-types-lightclients-tendermint/src/error.rs        | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/crates/ibc-types-lightclients-tendermint/src/client_state.rs b/crates/ibc-types-lightclients-tendermint/src/client_state.rs
index 93f116bb..0b2003a0 100644
--- a/crates/ibc-types-lightclients-tendermint/src/client_state.rs
+++ b/crates/ibc-types-lightclients-tendermint/src/client_state.rs
@@ -79,6 +79,10 @@ impl ClientState {
             });
         }
 
+        if chain_id.as_str() == "" {
+            return Err(Error::ChainIdEmpty);
+        }
+
         // `TrustThreshold` is guaranteed to be in the range `[0, 1)`, but a `TrustThreshold::ZERO`
         // value is invalid in this context
         if trust_level == TrustThreshold::ZERO {
diff --git a/crates/ibc-types-lightclients-tendermint/src/error.rs b/crates/ibc-types-lightclients-tendermint/src/error.rs
index 2fb2420a..8e71652d 100644
--- a/crates/ibc-types-lightclients-tendermint/src/error.rs
+++ b/crates/ibc-types-lightclients-tendermint/src/error.rs
@@ -22,6 +22,8 @@ pub enum Error {
         len: usize,
         max_len: usize,
     },
+    /// Chain ID cannot be empty
+    ChainIdEmpty,
     /// invalid header, failed basic validation: `{reason}`, error: `{error}`
     InvalidHeader {
         reason: String,