fix: Acquire lock on getClosedLedgerHash

src/test/app/LedgerReplay_test.cpp

@@ -333,7 +333,7 @@ public:
     setPublisherListSequence(PublicKey const&, std::size_t const) override
     {
     }
-    [[nodiscard]] uint256 const&
+    [[nodiscard]] uint256
     getClosedLedgerHash() const override
     {
         static uint256 const kHash{};

src/test/overlay/reduce_relay_test.cpp

@@ -140,7 +140,7 @@ public:
     setPublisherListSequence(PublicKey const&, std::size_t const) override
     {
     }
-    [[nodiscard]] uint256 const&
+    [[nodiscard]] uint256
     getClosedLedgerHash() const override
     {
         static uint256 const kHash{};

src/xrpld/overlay/Peer.h

@@ -117,7 +117,7 @@ public:
     // Ledger
     //
 
-    [[nodiscard]] virtual uint256 const&
+    [[nodiscard]] virtual uint256
     getClosedLedgerHash() const = 0;
     [[nodiscard]] virtual bool
     hasLedger(uint256 const& hash, std::uint32_t seq) const = 0;

src/xrpld/overlay/detail/PeerImp.h

@@ -426,9 +426,10 @@ public:
     // Ledger
     //
 
-    uint256 const&
+    uint256
     getClosedLedgerHash() const override
     {
+        std::scoped_lock const sl{recentLock_};
         return closedLedgerHash_;
     }