timeline: add exception to never splicing gaps

app/widget/timelinewidget/undo/timelineundopointer.cpp

@@ -340,7 +340,7 @@ void TrackPlaceBlockCommand::redo()
     // Place the Block at this point
     if (!ripple_remove_command_) {
       ripple_remove_command_ = new TrackRippleRemoveAreaCommand(track, TimeRange(in_, in_ + insert_->length()));
-
+      ripple_remove_command_->SetAllowSplittingGaps(true);
     }
 
     ripple_remove_command_->redo_now();

app/widget/timelinewidget/undo/timelineundoripple.cpp

@@ -30,6 +30,7 @@ namespace olive {
 TrackRippleRemoveAreaCommand::TrackRippleRemoveAreaCommand(Track* track, const TimeRange& range) :
   track_(track),
   range_(range),
+  allow_splitting_gaps_(false),
   splice_split_command_(nullptr)
 {
   trim_out_.block = nullptr;
@@ -63,7 +64,7 @@ void TrackRippleRemoveAreaCommand::prepare()
 
   // If it's getting trimmed, determine if it's actually getting spliced
   if (first_block_is_out_trimmed && first_block_is_in_trimmed) {
-    if (dynamic_cast<GapBlock*>(first_block)) {
+    if (!allow_splitting_gaps_ && dynamic_cast<GapBlock*>(first_block)) {
       // As a rule, we don't split gaps, so we just treat it as a trim of the range requested
       trim_out_ = {first_block,
                    first_block->length(),

app/widget/timelinewidget/undo/timelineundoripple.h

@@ -67,6 +67,11 @@ public:
     return nullptr;
   }
 
+  void SetAllowSplittingGaps(bool e)
+  {
+    allow_splitting_gaps_ = e;
+  }
+
 protected:
   virtual void prepare() override;
 
@@ -93,6 +98,7 @@ private:
   QVector<RemoveOperation> removals_;
   TrimOperation trim_in_;
   Block* insert_previous_;
+  bool allow_splitting_gaps_;
 
   BlockSplitCommand* splice_split_command_;
   QVector<UndoCommand*> remove_block_commands_;