Refactor the channel::self to point at the existing user

This way, the user is always up to date, instead of being a duplicate out of
sync.

fix #3258

src/irc/irc_channel.cpp

 #include <irc/irc_channel.hpp>
 #include <algorithm>
 
-void IrcChannel::set_self(const std::string& name)
+void IrcChannel::set_self(IrcUser* user)
 {
-  this->self = std::make_unique<IrcUser>(name);
+  this->self = user;
 }
 
 IrcUser* IrcChannel::add_user(const std::string& name,
                               const std::map<char, char>& prefix_to_mode)
 {
-  this->users.emplace_back(std::make_unique<IrcUser>(name, prefix_to_mode));
+  auto new_user = std::make_unique<IrcUser>(name, prefix_to_mode);
+  auto old_user = this->find_user(new_user->nick);
+  if (old_user)
+    return old_user;
+  this->users.emplace_back(std::move(new_user));
   return this->users.back().get();
 }
 
 IrcUser* IrcChannel::get_self() const
 {
-  return this->self.get();
+  return this->self;
 }
 
 IrcUser* IrcChannel::find_user(const std::string& name) const
@@ -32,19 +36,27 @@ IrcUser* IrcChannel::find_user(const std::string& name) const
 void IrcChannel::remove_user(const IrcUser* user)
 {
   const auto nick = user->nick;
+  const bool is_self = (user == this->self);
   const auto it = std::find_if(this->users.begin(), this->users.end(),
                                [nick](const std::unique_ptr<IrcUser>& u)
                                {
                                  return nick == u->nick;
                                });
   if (it != this->users.end())
-    this->users.erase(it);
+    {
+      this->users.erase(it);
+      if (is_self)
+        {
+          this->self = nullptr;
+          this->joined = false;
+        }
+    }
 }
 
 void IrcChannel::remove_all_users()
 {
   this->users.clear();
-  this->self.reset();
+  this->self = nullptr;
 }
 
 DummyIrcChannel::DummyIrcChannel():

src/irc/irc_channel.hpp

@@ -27,7 +27,7 @@ public:
   bool parting{false};
   std::string topic{};
   std::string topic_author{};
-  void set_self(const std::string& name);
+  void set_self(IrcUser* user);
   IrcUser* get_self() const;
   IrcUser* add_user(const std::string& name,
                     const std::map<char, char>& prefix_to_mode);
@@ -38,7 +38,8 @@ public:
   { return this->users; }
 
 protected:
-  std::unique_ptr<IrcUser> self{};
+  // Pointer to one IrcUser stored in users
+  IrcUser* self{nullptr};
   std::vector<std::unique_ptr<IrcUser>> users{};
 };
 

src/irc/irc_client.cpp

@@ -642,15 +642,18 @@ void IrcClient::set_and_forward_user_list(const IrcMessage& message)
   std::vector<std::string> nicks = utils::split(message.arguments[3], ' ');
   for (const std::string& nick: nicks)
     {
-      const IrcUser* user = channel->add_user(nick, this->prefix_to_mode);
-      if (user->nick != channel->get_self()->nick)
+      // Just create this dummy user to parse and get its modes
+      IrcUser tmp_user{nick, this->prefix_to_mode};
+      // Does this concern ourself
+      if (channel->get_self() && channel->find_user(tmp_user.nick) == channel->get_self())
         {
-          this->bridge.send_user_join(this->hostname, chan_name, user, user->get_most_significant_mode(this->sorted_user_modes), false);
+          // We now know our own modes, that’s all.
+          channel->get_self()->modes = tmp_user.modes;
         }
       else
-        {
-          // we now know the modes of self, so copy the modes into self
-          channel->get_self()->modes = user->modes;
+        { // Otherwise this is a new user
+          const IrcUser *user = channel->add_user(nick, this->prefix_to_mode);
+          this->bridge.send_user_join(this->hostname, chan_name, user, user->get_most_significant_mode(this->sorted_user_modes), false);
         }
     }
 }
@@ -664,13 +667,11 @@ void IrcClient::on_channel_join(const IrcMessage& message)
   else
     channel = this->get_channel(chan_name);
   const std::string nick = message.prefix;
+  IrcUser* user = channel->add_user(nick, this->prefix_to_mode);
   if (channel->joined == false)
-    channel->set_self(nick);
+    channel->set_self(user);
   else
-    {
-      const IrcUser* user = channel->add_user(nick, this->prefix_to_mode);
-      this->bridge.send_user_join(this->hostname, chan_name, user, user->get_most_significant_mode(this->sorted_user_modes), false);
-    }
+    this->bridge.send_user_join(this->hostname, chan_name, user, user->get_most_significant_mode(this->sorted_user_modes), false);
 }
 
 void IrcClient::on_channel_message(const IrcMessage& message)
@@ -929,15 +930,14 @@ void IrcClient::on_part(const IrcMessage& message)
   if (user)
     {
       std::string nick = user->nick;
+      bool self = channel->get_self() && channel->get_self()->nick == nick;
       channel->remove_user(user);
       Iid iid;
       iid.set_local(chan_name);
       iid.set_server(this->hostname);
       iid.type = Iid::Type::Channel;
-      bool self = channel->get_self()->nick == nick;
       if (self)
       {
-        channel->joined = false;
         this->channels.erase(utils::tolower(chan_name));
         // channel pointer is now invalid
         channel = nullptr;