db/update/Service: wrap UpdateWalk in std::unique_ptr<>

src/db/update/Service.cxx

@@ -56,8 +56,6 @@ UpdateService::~UpdateService()
 
 	if (update_thread.IsDefined())
 		update_thread.Join();
-
-	delete walk;
 }
 
 void
@@ -151,7 +149,8 @@ UpdateService::StartThread(UpdateQueueItem &&i)
 	modified = false;
 
 	next = std::move(i);
-	walk = new UpdateWalk(config, GetEventLoop(), listener, *next.storage);
+	walk = std::make_unique<UpdateWalk>(config, GetEventLoop(), listener,
+					    *next.storage);
 
 	update_thread.Start();
 
@@ -248,8 +247,7 @@ UpdateService::RunDeferred() noexcept
 	if (update_thread.IsDefined())
 		update_thread.Join();
 
-	delete walk;
-	walk = nullptr;
+	walk.reset();
 
 	next.Clear();
 

src/db/update/Service.hxx

@@ -26,6 +26,8 @@
 #include "thread/Thread.hxx"
 #include "util/Compiler.h"
 
+#include <memory>
+
 class SimpleDatabase;
 class DatabaseListener;
 class UpdateWalk;
@@ -56,7 +58,7 @@ class UpdateService final {
 
 	UpdateQueueItem next;
 
-	UpdateWalk *walk = nullptr;
+	std::unique_ptr<UpdateWalk> walk;
 
 public:
 	UpdateService(const ConfigData &_config,