From 386059258ab856d502ad72b917237c67887cddb5 Mon Sep 17 00:00:00 2001
From: Andrey Zvonov <32552679+zvonand@users.noreply.github.com>
Date: Fri, 26 Dec 2025 23:36:25 +0100
Subject: [PATCH] Merge pull request #1255 from
 Altinity/backports/25.8.13/90243

25.8.13 Stable backport of #90243: Fix crash in StorageDistributed when parsing malformed shard directory names
---
 src/Storages/StorageDistributed.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/Storages/StorageDistributed.cpp b/src/Storages/StorageDistributed.cpp
index f5b86d8f783f..761c152cb6da 100644
--- a/src/Storages/StorageDistributed.cpp
+++ b/src/Storages/StorageDistributed.cpp
@@ -1690,9 +1690,11 @@ Cluster::Addresses StorageDistributed::parseAddresses(const std::string & name)
                 continue;
             }
 
-            if (address.replica_index > replicas)
+            if (address.replica_index == 0 || address.replica_index > replicas)
             {
-                LOG_ERROR(log, "No shard with replica_index={} ({})", address.replica_index, name);
+                LOG_ERROR(log, "Invalid replica_index={} for directory '{}' (cluster has {} replicas for shard {}). "
+                               "Expected directory format: 'shardN_replicaM' or 'shardN_all_replicas'",
+                                address.replica_index, dirname, replicas, address.shard_index);
                 continue;
             }