Improve Database API to avoid memory leaks in the future, part 3.

This commit reworks SqlQueryHolder to return a unique_ptr instead of a
raw pointer to the query's result in its API.

src/framework/Utilities/Callback.h

@@ -20,6 +20,7 @@
 #define MANGOS_CALLBACK_H
 
 #include <functional>
+#include <memory>
 
 /// ---------- QUERY CALLBACKS -----------
 
@@ -33,7 +34,7 @@ namespace MaNGOS
 
             virtual ~IQueryCallback() = default;
             virtual void Execute() = 0;
-            virtual void SetResult(QueryResult* queryResult) = 0;
+            virtual void SetResult(std::unique_ptr<QueryResult> queryResult) = 0;
     };
 
     class QueryCallback : public IQueryCallback
@@ -54,18 +55,18 @@ namespace MaNGOS
 
             void Execute() override
             {
-                m_Callback(m_QueryResult);
+                m_Callback(m_QueryResult.release());
             }
 
-            void SetResult(QueryResult* queryResult) override
+            void SetResult(std::unique_ptr<QueryResult> queryResult) override
             {
-                m_QueryResult = queryResult;
+                m_QueryResult = std::move(queryResult);
             }
 
         private:
 
             std::function<void(QueryResult*)> m_Callback;
-            QueryResult* m_QueryResult;
+            std::unique_ptr<QueryResult> m_QueryResult;
     };
 }
 

src/game/Achievements/AchievementMgr.cpp

@@ -626,7 +626,7 @@ void AchievementMgr::SaveToDB()
     }
 }
 
-void AchievementMgr::LoadFromDB(QueryResult* achievementResult, QueryResult* criteriaResult)
+void AchievementMgr::LoadFromDB(std::unique_ptr<QueryResult> achievementResult, std::unique_ptr<QueryResult> criteriaResult)
 {
     // Note: this code called before any character data loading so don't must triggering any events req. inventory/etc
     // all like cases must be happens in CheckAllAchievementCriteria called after character data load
@@ -648,7 +648,6 @@ void AchievementMgr::LoadFromDB(QueryResult* achievementResult, QueryResult* cri
             ca.changed = false;
         }
         while (achievementResult->NextRow());
-        delete achievementResult;
     }
 
     if (criteriaResult)
@@ -704,7 +703,6 @@ void AchievementMgr::LoadFromDB(QueryResult* achievementResult, QueryResult* cri
             }
         }
         while (criteriaResult->NextRow());
-        delete criteriaResult;
     }
 }
 

src/game/Achievements/AchievementMgr.h

@@ -25,6 +25,7 @@
 #include "Entities/ObjectGuid.h"
 
 #include <map>
+#include <memory>
 
 struct AchievementEntry;
 struct AchievementCriteriaEntry;
@@ -280,7 +281,7 @@ class AchievementMgr
 
         void Reset();
         static void DeleteFromDB(ObjectGuid guid);
-        void LoadFromDB(QueryResult* achievementResult, QueryResult* criteriaResult);
+        void LoadFromDB(std::unique_ptr<QueryResult> achievementResult, std::unique_ptr<QueryResult> criteriaResult);
         void SaveToDB();
         void ResetAchievementCriteria(AchievementCriteriaTypes type, uint32 miscvalue1 = 0, uint32 miscvalue2 = 0);
         void StartTimedAchievementCriteria(AchievementCriteriaTypes type, uint32 timedRequirementId, time_t startTime = 0);

src/game/Entities/CharacterHandler.cpp

@@ -737,14 +737,13 @@ void WorldSession::HandlePlayerLogin(LoginQueryHolder* holder)
     SendOfflineNameQueryResponses();
 
     // QueryResult *result = CharacterDatabase.PQuery("SELECT guildid,rank FROM guild_member WHERE guid = '%u'",pCurrChar->GetGUIDLow());
-    QueryResult* resultGuild = holder->GetResult(PLAYER_LOGIN_QUERY_LOADGUILD);
+    auto resultGuild = holder->GetResult(PLAYER_LOGIN_QUERY_LOADGUILD);
 
     if (resultGuild)
     {
         Field* fields = resultGuild->Fetch();
         pCurrChar->SetInGuild(fields[0].GetUInt32());
         pCurrChar->SetRank(fields[1].GetUInt32());
-        delete resultGuild;
     }
     else if (pCurrChar->GetGuildId())                       // clear guild related fields in case wrong data about nonexistent membership
     {