From 31b77344078a6a65dec6b2ceaba6923f9f4d7138 Mon Sep 17 00:00:00 2001
From: Maksim Kita <kitaetoya@gmail.com>
Date: Fri, 19 Mar 2021 00:26:02 +0300
Subject: [PATCH] LRUCache fix exception unsafe element insertion

---
 src/Common/LRUCache.h | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/Common/LRUCache.h b/src/Common/LRUCache.h
index d75c8caf1fc..012ab7fe6c4 100644
--- a/src/Common/LRUCache.h
+++ b/src/Common/LRUCache.h
@@ -271,16 +271,23 @@ private:
 
     void setImpl(const Key & key, const MappedPtr & mapped, [[maybe_unused]] std::lock_guard<std::mutex> & cache_lock)
     {
-        auto res = cells.emplace(std::piecewise_construct,
+        auto [it, inserted] = cells.emplace(std::piecewise_construct,
             std::forward_as_tuple(key),
             std::forward_as_tuple());
 
-        Cell & cell = res.first->second;
-        bool inserted = res.second;
+        Cell & cell = it->second;
 
         if (inserted)
         {
-            cell.queue_iterator = queue.insert(queue.end(), key);
+            try
+            {
+                cell.queue_iterator = queue.insert(queue.end(), key);
+            }
+            catch (...)
+            {
+                cells.erase(it);
+                throw;
+            }
         }
         else
         {