Fix crash cutting a grouped subtitle

src/bin/model/subtitlemodel.cpp

@@ -502,7 +502,7 @@ bool SubtitleModel::cutSubtitle(int position)
 {
     Fun redo = []() { return true; };
     Fun undo = []() { return true; };
-    if (cutSubtitle(position, undo, redo)) {
+    if (cutSubtitle(position, undo, redo) > -1) {
         pCore->pushUndo(undo, redo, i18n("Cut clip"));
         return true;
     }

src/timeline2/model/timelinefunctions.cpp

@@ -127,7 +127,8 @@ bool TimelineFunctions::processClipCut(const std::shared_ptr<TimelineItemModel>
         return false;
     }
     if (isSubtitle) {
-        return timeline->cutSubtitle(position, undo, redo);
+        newId = timeline->cutSubtitle(position, undo, redo);
+        return newId > -1;
     }
     PlaylistState::ClipState state = timeline->m_allClips[clipId]->clipState();
     // Check if clip has an end Mix

src/timeline2/model/timelinemodel.cpp

@@ -1170,12 +1170,12 @@ bool TimelineModel::requestClipMove(int clipId, int trackId, int position, bool
     return res;
 }
 
-bool TimelineModel::cutSubtitle(int position, Fun &undo, Fun &redo)
+int TimelineModel::cutSubtitle(int position, Fun &undo, Fun &redo)
 {
     if (m_subtitleModel) {
         return m_subtitleModel->cutSubtitle(position, undo, redo);
     }
-    return false;
+    return -1;
 }
 
 bool TimelineModel::requestSubtitleMove(int clipId, int position, bool updateView, bool logUndo, bool invalidateTimeline)

src/timeline2/model/timelinemodel.hpp

@@ -368,7 +368,7 @@ public:
     Q_INVOKABLE bool requestClipMove(int clipId, int trackId, int position, bool moveMirrorTracks = true, bool updateView = true, bool logUndo = true, bool invalidateTimeline = false, bool revertMove = false);
     Q_INVOKABLE bool requestSubtitleMove(int clipId, int position, bool updateView = true, bool logUndo = true, bool invalidateTimeline = false);
     bool requestSubtitleMove(int clipId, int position, bool updateView, bool first, bool last, bool invalidateTimeline, Fun &undo, Fun &redo);
-    bool cutSubtitle(int position, Fun &undo, Fun &redo);
+    int cutSubtitle(int position, Fun &undo, Fun &redo);
     bool requestClipMix(const QString &mixId, std::pair<int, int> clipIds, std::pair<int, int> mixDurations, int trackId, int position, bool updateView, bool invalidateTimeline, bool finalMove, Fun &undo, Fun &redo, bool groupMove);
 
     /** @brief Move a composition to a specific position This action is undoable