Fix crash when closing and quickly opening a split, then running /clearmessages (#3852)

src/controllers/commands/CommandController.cpp

@@ -932,7 +932,11 @@ void CommandController::initialize(Settings &, Paths &paths)
         auto *currentPage = dynamic_cast<SplitContainer *>(
             getApp()->windows->getMainWindow().getNotebook().getSelectedPage());
 
-        currentPage->getSelectedSplit()->getChannelView().clearMessages();
+        if (auto split = currentPage->getSelectedSplit())
+        {
+            split->getChannelView().clearMessages();
+        }
+
         return "";
     });
 

src/widgets/Window.cpp

@@ -408,12 +408,13 @@ void Window::addShortcuts()
              {
                  splitContainer = this->notebook_->getOrAddSelectedPage();
              }
-             this->notebook_->select(splitContainer);
              Split *split = new Split(splitContainer);
              split->setChannel(
                  getApp()->twitch->getOrAddChannel(si.channelName));
              split->setFilters(si.filters);
              splitContainer->appendSplit(split);
+             splitContainer->setSelected(split);
+             this->notebook_->select(splitContainer);
              return "";
          }},
         {"toggleLocalR9K",