Loading a project with locked tracks should not insert an entry in undo history

src/timeline2/model/builders/meltBuilder.cpp

@@ -258,7 +258,7 @@ bool constructTimelineFromMelt(const std::shared_ptr<TimelineItemModel> &timelin
 
     // load locked state as last step
     for (int tid : qAsConst(lockedTracksIndexes)) {
-        timeline->setTrackLockedState(tid, true);
+        timeline->lockTrack(tid, true);
     }
 
     if (!ok) {

src/timeline2/model/timelinemodel.cpp

@@ -6060,6 +6060,15 @@ bool TimelineModel::requestSetSelection(const std::unordered_set<int> &ids, Fun
     return false;
 }
 
+void TimelineModel::lockTrack(int trackId, bool lock)
+{
+    if (lock) {
+        getTrackById(trackId)->lock();
+    } else {
+        getTrackById(trackId)->unlock();
+    }
+}
+
 void TimelineModel::setTrackLockedState(int trackId, bool lock)
 {
     QWriteLocker locker(&m_lock);
@@ -6068,11 +6077,11 @@ void TimelineModel::setTrackLockedState(int trackId, bool lock)
     Fun redo = []() { return true; };
 
     Fun lock_lambda = [this, trackId]() {
-        getTrackById(trackId)->lock();
+        lockTrack(trackId, true);
         return true;
     };
     Fun unlock_lambda = [this, trackId]() {
-        getTrackById(trackId)->unlock();
+        lockTrack(trackId, false);
         return true;
     };
     if (lock) {

src/timeline2/model/timelinemodel.hpp

@@ -459,6 +459,10 @@ public:
      */
     const QString sceneList(const QString &root, const QString &fullPath = QString(), const QString &filterData = QString());
 
+    /**  @brief Lock or unlock a track
+     */
+    void lockTrack(int trackId, bool lock);
+
 protected:
     /** @brief Creates a new clip instance without inserting it.
        This action is undoable, returns true on success