Fix crash that can occur when changing channels (Chatterino#3799)

The signal that handled the splitinput completer never disconnected, so
if it closed it would access bad memory

CHANGELOG.md

@@ -8,7 +8,6 @@
 - Minor: Adjust large stream thumbnail to 16:9 (#3655)
 - Minor: Fixed being unable to load Twitch Usercards from the `/mentions` tab. (#3623)
 - Minor: Add information about the user's operating system in the About page. (#3663)
-- Bugfix: Connection to Twitch PubSub now recovers more reliably. (#3643, #3716)
 - Minor: Added chatter count for each category in viewer list. (#3683, #3719)
 - Minor: Sorted usernames in /vips message to be case-insensitive. (#3696)
 - Minor: Added option to open a user's chat in a new tab from the usercard profile picture context menu. (#3625)
@@ -21,6 +20,8 @@
 - Minor: Added ability to execute commands on chat messages using the message context menu. (#3738, #3765)
 - Minor: Added `/copy` command. Usage: `/copy <text>`. Copies provided text to clipboard - can be useful with custom commands. (#3763)
 - Minor: Removed total views from the usercard, as Twitch no longer updates the number. (#3792)
+- Bugfix: Connection to Twitch PubSub now recovers more reliably. (#3643, #3716)
+- Bugfix: Fix crash that can occur when changing channels. (#3799)
 - Bugfix: Fixed viewers list search not working when used before loading finishes. (#3774)
 - Bugfix: Fixed live notifications for usernames containing uppercase characters. (#3646)
 - Bugfix: Fixed live notifications not getting updated for closed streams going offline. (#3678)

src/widgets/splits/SplitInput.cpp

@@ -40,9 +40,9 @@ SplitInput::SplitInput(Split *_chatWidget)
         new QCompleter(&this->split_->getChannel().get()->completionModel);
     this->ui_.textEdit->setCompleter(completer);
 
-    this->split_->channelChanged.connect([this] {
-        auto completer =
-            new QCompleter(&this->split_->getChannel()->completionModel);
+    this->signalHolder_.managedConnect(this->split_->channelChanged, [this] {
+        auto channel = this->split_->getChannel();
+        auto completer = new QCompleter(&channel->completionModel);
         this->ui_.textEdit->setCompleter(completer);
     });