LocalStorage: Return new version of DB from changeVersion()

This is probably what you want if you change the version of the
database. Without this, you need to reopen the connection, which makes
the code ugly.

Fixes: QTBUG-71838
Change-Id: I6f1e118ba8e102d1043c4658d036c144bbde7229
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

1 files changed, 17 insertions, 10 deletions

diff --git a/src/imports/localstorage/plugin.cpp b/src/imports/localstorage/plugin.cpp
index e7e8d130bb..3c34d8e45a 100644
--- a/src/imports/localstorage/plugin.cpp
+++ b/src/imports/localstorage/plugin.cpp
@@ -399,23 +399,23 @@ static ReturnedValue qmlsqldatabase_changeVersion(const FunctionObject *b, const
     if (from_version != *r->d()->version)
         V4THROW_SQL(SQLEXCEPTION_VERSION_ERR, QQmlEngine::tr("Version mismatch: expected %1, found %2").arg(from_version).arg(*r->d()->version));
 
-    Scoped<QQmlSqlDatabaseWrapper> w(scope, QQmlSqlDatabaseWrapper::create(scope.engine));
-    ScopedObject p(scope, databaseData(scope.engine)->queryProto.value());
-    w->setPrototypeUnchecked(p.getPointer());
-    w->d()->type = Heap::QQmlSqlDatabaseWrapper::Query;
-    *w->d()->database = db;
-    *w->d()->version = *r->d()->version;
-
     bool ok = true;
     if (!!callback) {
+        Scoped<QQmlSqlDatabaseWrapper> query(scope, QQmlSqlDatabaseWrapper::create(scope.engine));
+        ScopedObject p(scope, databaseData(scope.engine)->queryProto.value());
+        query->setPrototypeUnchecked(p.getPointer());
+        query->d()->type = Heap::QQmlSqlDatabaseWrapper::Query;
+        *query->d()->database = db;
+        *query->d()->version = *r->d()->version;
+
         ok = false;
         db.transaction();
 
         JSCallData jsCall(scope, 1);
         *jsCall->thisObject = scope.engine->globalObject;
-        jsCall->args[0] = w;
+        jsCall->args[0] = query;
 
-        TransactionRollback rollbackOnException(&db, &w->d()->inTransaction);
+        TransactionRollback rollbackOnException(&db, &query->d()->inTransaction);
         callback->call(jsCall);
         rollbackOnException.clear();
         if (!db.commit()) {
@@ -427,12 +427,18 @@ static ReturnedValue qmlsqldatabase_changeVersion(const FunctionObject *b, const
     }
 
     if (ok) {
+        Scoped<QQmlSqlDatabaseWrapper> w(scope, QQmlSqlDatabaseWrapper::create(scope.engine));
+        ScopedObject p(scope, databaseData(scope.engine)->databaseProto.value());
+        w->setPrototypeUnchecked(p.getPointer());
+        w->d()->type = Heap::QQmlSqlDatabaseWrapper::Database;
+        *w->d()->database = db;
         *w->d()->version = to_version;
 #if QT_CONFIG(settings)
         const QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(scope.engine->qmlEngine());
         QSettings ini(enginePrivate->offlineStorageDatabaseDirectory() + db.connectionName() + QLatin1String(".ini"), QSettings::IniFormat);
         ini.setValue(QLatin1String("Version"), to_version);
 #endif
+        RETURN_RESULT(w.asReturnedValue());
     }
 
     RETURN_UNDEFINED();
@@ -599,7 +605,8 @@ This data can be used by application tools.
 
 \section3 db.changeVersion(from, to, callback(tx))
 
-This method allows you to perform a \e{Scheme Upgrade}.
+This method allows you to perform a \e{Scheme Upgrade}. If it succeeds it returns a new
+database object of version \e to. Otherwise it returns \e undefined.
 
 If the current version of \e db is not \e from, then an exception is thrown.