CLI Merge: Only save database file when modified. (#2466)

* Merge: detect if database was changed.
* Adding unit test.
* Only saving on change.

src/cli/Merge.cpp

@@ -84,14 +84,18 @@ int Merge::execute(const QStringList& arguments)
     }
 
     Merger merger(db2.data(), db1.data());
-    merger.merge();
-
-    QString errorMessage = db1->saveToFile(args.at(0));
-    if (!errorMessage.isEmpty()) {
-        err << QObject::tr("Unable to save database to file : %1").arg(errorMessage) << endl;
-        return EXIT_FAILURE;
+    bool databaseChanged = merger.merge();
+
+    if (databaseChanged) {
+        QString errorMessage = db1->saveToFile(args.at(0));
+        if (!errorMessage.isEmpty()) {
+            err << QObject::tr("Unable to save database to file : %1").arg(errorMessage) << endl;
+            return EXIT_FAILURE;
+        }
+        out << "Successfully merged the database files." << endl;
+    } else {
+        out << "Database was not modified by merge operation." << endl;
     }
 
-    out << "Successfully merged the database files." << endl;
     return EXIT_SUCCESS;
 }

tests/TestCli.cpp

@@ -698,6 +698,15 @@ void TestCli::testMerge()
     QVERIFY(entry1);
     QCOMPARE(entry1->title(), QString("Some Website"));
     QCOMPARE(entry1->password(), QString("secretsecretsecret"));
+
+    // making sure that the message is different if the database was not
+    // modified by the merge operation.
+    pos = m_stdoutFile->pos();
+    Utils::Test::setNextPassword("a");
+    mergeCmd.execute({"merge", "-s", sourceFile.fileName(), sourceFile.fileName()});
+    m_stdoutFile->seek(pos);
+    m_stdoutFile->readLine();
+    QCOMPARE(m_stdoutFile->readAll(), QByteArray("Database was not modified by merge operation.\n"));
 }
 
 void TestCli::testRemove()