fix #279662: fixup for aeb4919

Copying of some selection information is still needed when selection
state can be modified. This commit reverts back to copying Selection
object in such cases.

libmscore/edit.cpp

@@ -1254,7 +1254,7 @@ void Score::cmdAddTie(bool addToChord)
 
 void Score::cmdAddOttava(OttavaType type)
       {
-      const Selection& sel = selection();
+      const Selection sel = selection(); // copy selection state before the operation.
       // add on each staff if possible
       if (sel.isRange() && sel.staffStart() != sel.staffEnd() - 1) {
             for (int staffIdx = sel.staffStart() ; staffIdx < sel.staffEnd(); ++staffIdx) {

mscore/palette.cpp

@@ -456,7 +456,7 @@ void Palette::applyPaletteElement(PaletteCell* cell, Qt::KeyboardModifiers modif
       Score* score = mscore->currentScore();
       if (score == 0)
             return;
-      const Selection& sel = score->selection();       // make a copy of the list
+      const Selection sel = score->selection(); // make a copy of selection state before applying the operation.
       if (sel.isNone())
             return;
 

mscore/scoreview.cpp

@@ -3330,8 +3330,7 @@ void ScoreView::cmdAddNoteLine()
 void ScoreView::cmdChangeEnharmonic(bool both)
       {
       _score->startCmd();
-      Selection& selection = _score->selection();
-      QList<Note*> notes = selection.uniqueNotes();
+      QList<Note*> notes = _score->selection().uniqueNotes();
       for (Note* n : notes) {
             Staff* staff = n->staff();
             if (staff->part()->instrument()->useDrumset())
@@ -3392,6 +3391,7 @@ void ScoreView::cmdChangeEnharmonic(bool both)
                   }
             }
 
+      Selection& selection = _score->selection();
       selection.clear();
       for (Note* n : notes)
             selection.add(n);