Fixed triggering mode change when acquiring

src/export.cpp

@@ -98,11 +98,13 @@ ExportTable collect_export(ScopeModel& model, RowSet& rows) {
                                                      : std::string("ch") + std::to_string(c);
   };
 
-  // What the rows bind to is what gets exported, which is the same branch `RowSet::bind()`
-  // takes: the frozen event in trigger mode, the live ring otherwise. Reading the ring
-  // while an event is on screen would export data the user cannot see.
+  // What the rows bind to is what gets exported, so the split is the same `DisplayMode`
+  // `RowSet::bind()` switches on: the frozen event only while one is held, the live ring
+  // otherwise -- including mid-capture, where the rows follow the live ring too. Reading
+  // the ring while an event is on screen would export data the user cannot see, and
+  // reading the stale snapshot mid-capture would export the *previous* event.
   std::shared_ptr<const EventSnapshot> snap = model.event();
-  if (model.trigger_enabled() && snap != nullptr) {
+  if (model.display_mode() == DisplayMode::Held && snap != nullptr) {
     // The snapshot is immutable and already index-aligned, so the visible window is two
     // binary searches over its stamps and the same index range for every channel.
     const std::vector<f32>& st = snap->stamps;