From bdee748a6a0bbd8b9bdb461fc205177b5ed28675 Mon Sep 17 00:00:00 2001
From: Carlo Teubner <435950+c4rlo@users.noreply.github.com>
Date: Sat, 1 Dec 2018 21:08:55 +0000
Subject: [PATCH] Make Entry::m_tmpHistoryItem a QScopedPointer (#2524)

* Make m_tmpHistoryItem a QScopedPointer

Most of the time, `m_tmpHistoryItem` should be null by the time an
`Entry` is destroyed. However, if a caller ever calls `beginUpdate()`
without later calling `endUpdate()` -- perhaps because an exception was
throw in the meantime -- it may not be null. This change avoids a memory
leak in that case.

Found via https://lgtm.com/projects/g/keepassxreboot/keepassxc/alerts
---
 src/core/Entry.cpp | 13 +++++--------
 src/core/Entry.h   |  2 +-
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/src/core/Entry.cpp b/src/core/Entry.cpp
index 55f56f583..9eb25c278 100644
--- a/src/core/Entry.cpp
+++ b/src/core/Entry.cpp
@@ -40,7 +40,6 @@ Entry::Entry()
     , m_attachments(new EntryAttachments(this))
     , m_autoTypeAssociations(new AutoTypeAssociations(this))
     , m_customData(new CustomData(this))
-    , m_tmpHistoryItem(nullptr)
     , m_modifiedSinceBegin(false)
     , m_updateTimeinfo(true)
 {
@@ -706,9 +705,9 @@ void Entry::copyDataFrom(const Entry* other)
 
 void Entry::beginUpdate()
 {
-    Q_ASSERT(!m_tmpHistoryItem);
+    Q_ASSERT(m_tmpHistoryItem.isNull());
 
-    m_tmpHistoryItem = new Entry();
+    m_tmpHistoryItem.reset(new Entry());
     m_tmpHistoryItem->setUpdateTimeinfo(false);
     m_tmpHistoryItem->m_uuid = m_uuid;
     m_tmpHistoryItem->m_data = m_data;
@@ -721,16 +720,14 @@ void Entry::beginUpdate()
 
 bool Entry::endUpdate()
 {
-    Q_ASSERT(m_tmpHistoryItem);
+    Q_ASSERT(!m_tmpHistoryItem.isNull());
     if (m_modifiedSinceBegin) {
         m_tmpHistoryItem->setUpdateTimeinfo(true);
-        addHistoryItem(m_tmpHistoryItem);
+        addHistoryItem(m_tmpHistoryItem.take());
         truncateHistory();
-    } else {
-        delete m_tmpHistoryItem;
     }
 
-    m_tmpHistoryItem = nullptr;
+    m_tmpHistoryItem.reset();
 
     return m_modifiedSinceBegin;
 }
diff --git a/src/core/Entry.h b/src/core/Entry.h
index 655cc3621..ae11abe4d 100644
--- a/src/core/Entry.h
+++ b/src/core/Entry.h
@@ -249,7 +249,7 @@ private:
     QPointer<CustomData> m_customData;
     QList<Entry*> m_history; // Items sorted from oldest to newest
 
-    Entry* m_tmpHistoryItem;
+    QScopedPointer<Entry> m_tmpHistoryItem;
     bool m_modifiedSinceBegin;
     QPointer<Group> m_group;
     bool m_updateTimeinfo;