make sure scrollbar doesn't request messages out of scope

messages/limitedqueue.h

@@ -4,6 +4,7 @@
 #include "messages/limitedqueuesnapshot.h"
 
 #include <boost/signals2.hpp>
+
 #include <memory>
 #include <mutex>
 #include <vector>
@@ -102,7 +103,8 @@ private:
     int limit;
     int buffer;
 };
-}
-}
+
+}  // namespace messages
+}  // namespace chatterino
 
 #endif  // LIMITEDQUEUE_H

widgets/chatwidgetview.cpp

@@ -49,6 +49,17 @@ ChatWidgetView::layoutMessages()
 
     int start = this->scrollbar.getCurrentValue();
 
+    if (messages.getLength() <= start) {
+        // The scrollbar wants to show more values than we can offer
+
+        // just return for now
+        return false;
+
+
+        // Lower start value to the last message
+        // start = messages.getLength() - 1;
+    }
+
     int y = -(messages[start].get()->getHeight() *
               (fmod(this->scrollbar.getCurrentValue(), 1)));