Issue 657: CalChart on Mac crashes when last continuity for any dot type is deleted (#659)

Author: rmpowell77

LATEST_RELEASE_NOTES.md

@@ -3,6 +3,7 @@
 Bugs addressed in this release:
 
 * [#579](../../issues/579) Changing CalChart name in /Applications can make it loose the help system
+* [#657](../../issues/657) CalChart on Mac crashes when last continuity for any dot type is deleted
 * [#660](../../issues/660) Why are only some of the marchers selected in animation view
 
 Other changes:

src/CustomListViewPanel.cpp

@@ -193,6 +193,14 @@ CustomListViewPanel::CustomListViewPanel(wxWindow* parent, wxWindowID winid, wxP
 void CustomListViewPanel::SetCells(std::vector<std::unique_ptr<DrawableCell>> cells)
 {
     mCells = std::move(cells);
+    if (m_selected) {
+        if (mCells.empty()) {
+            m_selected = std::nullopt;
+        } else {
+            m_selected = std::min(*m_selected, mCells.size() - 1);
+        }
+    }
+
     auto total_y = std::accumulate(mCells.begin(), mCells.end(), 0, [](auto&& a, auto&& b) {
         return a + b->Height();
     });