fix potential crash & add vtest

libmscore/spanner.cpp

@@ -456,6 +456,10 @@ void Spanner::computeEndElement()
       switch (_anchor) {
             case Anchor::SEGMENT: {
                   _endElement = score()->findCRinStaff(tick2() - 1, track2());
+                  if (!_endElement) {
+                        qDebug("%s no end element for tick %d", name(), tick2());
+                        return;
+                        }
                   int nticks = endCR()->tick() + endCR()->actualTicks() - _tick;
                   if (_ticks != nticks) {
                         qDebug("%s ticks changed, %d -> %d", name(), _ticks, nticks);

vtest/gen

@@ -38,7 +38,7 @@ else
        emmentaler-text-1 gonville-text-1 bravura-text-1 musejazz-text-1\
        emmentaler-text-2 gonville-text-2 bravura-text-2 musejazz-text-2\
        emmentaler-text-3 gonville-text-3 bravura-text-3 musejazz-text-3\
-       frametext ottava slurs-1 slurs-2 slurs-3 hairpins-1 pedal-1 line-1 line-2 line-3 line-4 gliss-1 gliss-2\
+       frametext ottava slurs-1 slurs-2 slurs-3 hairpins-1 pedal-1 line-1 line-2 line-3 line-4 line-5 gliss-1 gliss-2\
        chord-layout-1 chord-layout-2 chord-layout-3 chord-layout-4 chord-layout-5\
        chord-layout-6 chord-layout-7 chord-layout-8 chord-layout-9 chord-layout-10\
        chord-layout-11 chord-layout-12 chord-layout-13 chord-layout-14 chord-layout-15 cross-1\

vtest/gen.bat

@@ -13,7 +13,7 @@ set SRC=mmrest-1,bravura-mmrest,gonville-mmrest,mmrest-2,mmrest-4,mmrest-5,mmres
  emmentaler-text-1,gonville-text-1,bravura-text-1,musejazz-text-1, ^
  emmentaler-text-2,gonville-text-2,bravura-text-2,musejazz-text-2, ^
  emmentaler-text-3,gonville-text-3,bravura-text-3,musejazz-text-3, ^
- frametext,ottava,slurs-1,slurs-2,slurs-3,hairpins-1,pedal-1,line-1,line-2,line-3,line-4,gliss-1,gliss-2, ^
+ frametext,ottava,slurs-1,slurs-2,slurs-3,hairpins-1,pedal-1,line-1,line-2,line-3,line-4,line-5,gliss-1,gliss-2, ^
  chord-layout-1,chord-layout-2,chord-layout-3,chord-layout-4,chord-layout-5, ^
  chord-layout-6,chord-layout-7,chord-layout-8,chord-layout-9,chord-layout-10, ^
  chord-layout-11,chord-layout-12,chord-layout-13,chord-layout-14,chord-layout-15,cross-1, ^