Implement 'Save Database Backup' option

Add an option in the 'Database' menu to save a backup of the current database.

Add unit test for saving database copy

* Open a test database, mark it as modified, and save a copy
* Fail if the copy is not a valid database
* Fail if the original database is saved
* Fail if the original database is no longer marked as modified

src/gui/DatabaseTabWidget.cpp

@@ -393,6 +393,20 @@ bool DatabaseTabWidget::saveDatabaseAs(int index)
     return ok;
 }
 
+bool DatabaseTabWidget::saveDatabaseBackup(int index)
+{
+    if (index == -1) {
+        index = currentIndex();
+    }
+
+    auto* dbWidget = databaseWidgetFromIndex(index);
+    bool ok = dbWidget->saveBackup();
+    if (ok) {
+        updateLastDatabases(dbWidget->database()->filePath());
+    }
+    return ok;
+}
+
 void DatabaseTabWidget::closeDatabaseFromSender()
 {
     auto* dbWidget = qobject_cast<DatabaseWidget*>(sender());

src/gui/DatabaseTabWidget.h

@@ -68,6 +68,7 @@ public slots:
     void importOpVaultDatabase();
     bool saveDatabase(int index = -1);
     bool saveDatabaseAs(int index = -1);
+    bool saveDatabaseBackup(int index = -1);
     void exportToCsv();
     void exportToHtml();
 

src/gui/DatabaseWidget.cpp

@@ -1866,6 +1866,53 @@ bool DatabaseWidget::saveAs()
     }
 }
 
+/**
+ * Save copy of database under a new user-selected filename.
+ *
+ * @return true on success
+ */
+bool DatabaseWidget::saveBackup()
+{
+    while (true) {
+        QString oldFilePath = m_db->filePath();
+        if (!QFileInfo::exists(oldFilePath)) {
+            oldFilePath = QDir::toNativeSeparators(config()->get(Config::LastDir).toString() + "/"
+                                                   + tr("Passwords").append(".kdbx"));
+        }
+        const QString newFilePath = fileDialog()->getSaveFileName(this,
+                                                                  tr("Save database backup"),
+                                                                  oldFilePath,
+                                                                  tr("KeePass 2 Database").append(" (*.kdbx)"),
+                                                                  nullptr,
+                                                                  nullptr);
+
+        if (!newFilePath.isEmpty()) {
+            // Ensure we don't recurse back into this function
+            m_db->setReadOnly(false);
+            m_db->setFilePath(newFilePath);
+            m_saveAttempts = 0;
+
+            bool modified = m_db->isModified();
+
+            if (!save()) {
+                // Failed to save, try again
+                m_db->setFilePath(oldFilePath);
+                continue;
+            }
+
+            m_db->setFilePath(oldFilePath);
+            if (modified) {
+                // Source database is marked as clean when copy is saved, even if source has unsaved changes
+                m_db->markAsModified();
+            }
+            return true;
+        }
+
+        // Canceled file selection
+        return false;
+    }
+}
+
 void DatabaseWidget::showMessage(const QString& text,
                                  MessageWidget::MessageType type,
                                  bool showClosebutton,

src/gui/DatabaseWidget.h

@@ -158,6 +158,7 @@ public slots:
     bool lock();
     bool save();
     bool saveAs();
+    bool saveBackup();
 
     void replaceDatabase(QSharedPointer<Database> db);
     void createEntry();

src/gui/MainWindow.cpp

@@ -324,6 +324,7 @@ MainWindow::MainWindow()
     m_ui->actionDatabaseOpen->setIcon(resources()->icon("document-open"));
     m_ui->actionDatabaseSave->setIcon(resources()->icon("document-save"));
     m_ui->actionDatabaseSaveAs->setIcon(resources()->icon("document-save-as"));
+    m_ui->actionDatabaseSaveBackup->setIcon(resources()->icon("document-save-copy"));
     m_ui->actionDatabaseClose->setIcon(resources()->icon("document-close"));
     m_ui->actionReports->setIcon(resources()->icon("reports"));
     m_ui->actionChangeDatabaseSettings->setIcon(resources()->icon("document-edit"));
@@ -396,6 +397,7 @@ MainWindow::MainWindow()
     connect(m_ui->actionDatabaseOpen, SIGNAL(triggered()), m_ui->tabWidget, SLOT(openDatabase()));
     connect(m_ui->actionDatabaseSave, SIGNAL(triggered()), m_ui->tabWidget, SLOT(saveDatabase()));
     connect(m_ui->actionDatabaseSaveAs, SIGNAL(triggered()), m_ui->tabWidget, SLOT(saveDatabaseAs()));
+    connect(m_ui->actionDatabaseSaveBackup, SIGNAL(triggered()), m_ui->tabWidget, SLOT(saveDatabaseBackup()));
     connect(m_ui->actionDatabaseClose, SIGNAL(triggered()), m_ui->tabWidget, SLOT(closeCurrentDatabaseTab()));
     connect(m_ui->actionDatabaseMerge, SIGNAL(triggered()), m_ui->tabWidget, SLOT(mergeDatabase()));
     connect(m_ui->actionChangeMasterKey, SIGNAL(triggered()), m_ui->tabWidget, SLOT(changeMasterKey()));
@@ -681,6 +683,7 @@ void MainWindow::setMenuActionState(DatabaseWidget::Mode mode)
             m_ui->actionChangeDatabaseSettings->setEnabled(true);
             m_ui->actionDatabaseSave->setEnabled(m_ui->tabWidget->canSave());
             m_ui->actionDatabaseSaveAs->setEnabled(true);
+            m_ui->actionDatabaseSaveBackup->setEnabled(true);
             m_ui->menuExport->setEnabled(true);
             m_ui->actionExportCsv->setEnabled(true);
             m_ui->actionExportHtml->setEnabled(true);
@@ -736,6 +739,7 @@ void MainWindow::setMenuActionState(DatabaseWidget::Mode mode)
             m_ui->actionChangeDatabaseSettings->setEnabled(false);
             m_ui->actionDatabaseSave->setEnabled(false);
             m_ui->actionDatabaseSaveAs->setEnabled(false);
+            m_ui->actionDatabaseSaveBackup->setEnabled(false);
             m_ui->menuExport->setEnabled(false);
             m_ui->actionExportCsv->setEnabled(false);
             m_ui->actionExportHtml->setEnabled(false);
@@ -764,6 +768,7 @@ void MainWindow::setMenuActionState(DatabaseWidget::Mode mode)
         m_ui->actionChangeDatabaseSettings->setEnabled(false);
         m_ui->actionDatabaseSave->setEnabled(false);
         m_ui->actionDatabaseSaveAs->setEnabled(false);
+        m_ui->actionDatabaseSaveBackup->setEnabled(false);
         m_ui->actionDatabaseClose->setEnabled(false);
         m_ui->menuExport->setEnabled(false);
         m_ui->actionExportCsv->setEnabled(false);

src/gui/MainWindow.ui

@@ -260,6 +260,7 @@
     <addaction name="menuRecentDatabases"/>
     <addaction name="actionDatabaseSave"/>
     <addaction name="actionDatabaseSaveAs"/>
+    <addaction name="actionDatabaseSaveBackup"/>
     <addaction name="actionDatabaseClose"/>
     <addaction name="separator"/>
     <addaction name="actionChangeMasterKey"/>
@@ -332,9 +333,6 @@
     <addaction name="separator"/>
     <addaction name="actionEntryOpenUrl"/>
     <addaction name="actionEntryDownloadIcon"/>
-    <addaction name="separator"/>
-    <addaction name="actionEntryAddToAgent"/>
-    <addaction name="actionEntryRemoveFromAgent"/>
    </widget>
    <widget class="QMenu" name="menuGroups">
     <property name="title">
@@ -808,6 +806,14 @@
     <string notr="true">Ctrl+/</string>
    </property>
   </action>
+  <action name="actionDatabaseSaveBackup">
+   <property name="enabled">
+    <bool>false</bool>
+   </property>
+   <property name="text">
+    <string>Save Database Backup...</string>
+   </property>
+  </action>
   <action name="actionEntryAddToAgent">
    <property name="text">
     <string>Add key to SSH Agent</string>