Remove linked elements on mmRests when moving segments

src/engraving/dom/textbase.cpp

@@ -3435,6 +3435,24 @@ bool TextBase::moveSegment(const EditData& ed)
 
 void TextBase::undoMoveSegment(Segment* newSeg, Fraction tickDiff)
 {
+    // NOTE: when creating mmRests, we clone text elements from the underlying measure onto the
+    // mmRest measure. This creates lots of additional linked copies which are hard to manage
+    // and can result in duplicates. Here we need to remove copies on mmRests because they are invalidated
+    // when moving segments (and if needed will be recreated at the next layout). In future we need to
+    // change approach and *move* elements onto the mmRests, not clone them. [M.S.]
+    std::list<EngravingObject*> linkedElements = linkList();
+    for (EngravingObject* linkedElement : linkedElements) {
+        if (linkedElement == this) {
+            continue;
+        }
+        Segment* curParent = toSegment(linkedElement->parent());
+        bool isOnMMRest = curParent->parent() && toMeasure(curParent->parent())->isMMRest();
+        if (isOnMMRest) {
+            linkedElement->undoUnlink();
+            score()->undoRemoveElement(static_cast<EngravingItem*>(linkedElement));
+        }
+    }
+
     score()->undoChangeParent(this, newSeg, staffIdx());
     moveSnappedItems(newSeg, tickDiff);
 }