Merge #3538

3538: Improve error messages when you can't join team r=heinrich5991 a=def-

<!-- What is the motivation for the changes of this pull request -->

## Checklist

- [x] Tested the change ingame
- [ ] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test if it works standalone, system.c especially
- [x] Considered possible null pointers and out of bounds array indexing
- [x] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: def <dennis@felsin9.de>

src/game/server/ddracechat.cpp

@@ -950,13 +950,7 @@ void CGameContext::ConJoinTeam(IConsole::IResult *pResult, void *pUserData)
 		{
 			int Team = pResult->GetInteger(0);
 
-			if(Team == pController->m_Teams.m_Core.Team(pResult->m_ClientID))
-			{
-				char aBuf[32];
-				str_format(aBuf, sizeof(aBuf), "You are in team %d already", Team);
-				pSelf->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "join", aBuf);
-			}
-			else if(pPlayer->m_Last_Team + (int64_t)pSelf->Server()->TickSpeed() * g_Config.m_SvTeamChangeDelay > pSelf->Server()->Tick())
+			if(pPlayer->m_Last_Team + (int64_t)pSelf->Server()->TickSpeed() * g_Config.m_SvTeamChangeDelay > pSelf->Server()->Tick())
 			{
 				pSelf->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "join",
 					"You can\'t change teams that fast!");
@@ -974,7 +968,11 @@ void CGameContext::ConJoinTeam(IConsole::IResult *pResult, void *pUserData)
 				str_format(aBuf, sizeof(aBuf), "This team already has the maximum allowed size of %d players", g_Config.m_SvTeamMaxSize);
 				pSelf->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "join", aBuf);
 			}
-			else if(pController->m_Teams.SetCharacterTeam(pPlayer->GetCID(), Team))
+			else if(const char *pError = pController->m_Teams.SetCharacterTeam(pPlayer->GetCID(), Team))
+			{
+				pSelf->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "join", pError);
+			}
+			else
 			{
 				char aBuf[512];
 				str_format(aBuf, sizeof(aBuf), "%s joined team %d",
@@ -986,11 +984,6 @@ void CGameContext::ConJoinTeam(IConsole::IResult *pResult, void *pUserData)
 				if(pController->m_Teams.IsPractice(Team))
 					pSelf->SendChatTarget(pPlayer->GetCID(), "Practice mode enabled for your team, happy practicing!");
 			}
-			else
-			{
-				pSelf->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "join",
-					"You cannot join this team at this time");
-			}
 		}
 	}
 	else

src/game/server/teams.cpp

@@ -230,43 +230,40 @@ void CGameTeams::CheckTeamFinished(int Team)
 			for(unsigned int i = 0; i < PlayersCount; ++i)
 				OnFinish(TeamPlayers[i], Time, aTimestamp);
 			ChangeTeamState(Team, TEAMSTATE_FINISHED); // TODO: Make it better
-			//ChangeTeamState(Team, TEAMSTATE_OPEN);
 			OnTeamFinish(TeamPlayers, PlayersCount, Time, aTimestamp);
 		}
 	}
 }
 
-bool CGameTeams::SetCharacterTeam(int ClientID, int Team)
+const char *CGameTeams::SetCharacterTeam(int ClientID, int Team)
 {
-	//Check on wrong parameters. +1 for TEAM_SUPER
-	if(ClientID < 0 || ClientID >= MAX_CLIENTS || Team < 0 || Team >= MAX_CLIENTS + 1)
-		return false;
-	//You can join to TEAM_SUPER at any time, but any other group you cannot if it started
+	if(ClientID < 0 || ClientID >= MAX_CLIENTS)
+		return "Invalid client ID";
+	if(Team < 0 || Team >= MAX_CLIENTS + 1)
+		return "Invalid team number";
 	if(Team != TEAM_SUPER && m_TeamState[Team] > TEAMSTATE_OPEN)
-		return false;
-	//No need to switch team if you there
+		return "This team started already";
 	if(m_Core.Team(ClientID) == Team)
-		return false;
+		return "You are in this team already";
 	if(!Character(ClientID))
-		return false;
-	//You cannot be in TEAM_SUPER if you not super
+		return "Your character is not valid";
 	if(Team == TEAM_SUPER && !Character(ClientID)->m_Super)
-		return false;
-	//if you begin race
-	if(Character(ClientID)->m_DDRaceState != DDRACE_NONE && Team != TEAM_SUPER)
-		return false;
+		return "You can't join super team if you don't have super rights";
+	if(Team != TEAM_SUPER && Character(ClientID)->m_DDRaceState != DDRACE_NONE)
+		return "You have started racing already";
 	// No cheating through noob filter with practice and then leaving team
 	if(m_Practice[m_Core.Team(ClientID)])
-		return false;
+		return "You have used practice mode already";
 
 	// you can not join a team which is currently in the process of saving,
 	// because the save-process can fail and then the team is reset into the game
-	if((Team != TEAM_SUPER && GetSaving(Team)) || (m_Core.Team(ClientID) != TEAM_SUPER && GetSaving(m_Core.Team(ClientID))))
-		return false;
-	SetForceCharacterTeam(ClientID, Team);
+	if(Team != TEAM_SUPER && GetSaving(Team))
+		return "Your team is currently saving";
+	if(m_Core.Team(ClientID) != TEAM_SUPER && GetSaving(m_Core.Team(ClientID)))
+		return "This team is currently saving";
 
-	//GameServer()->CreatePlayerSpawn(Character(id)->m_Core.m_Pos, TeamMask());
-	return true;
+	SetForceCharacterTeam(ClientID, Team);
+	return nullptr;
 }
 
 void CGameTeams::SetForceCharacterTeam(int ClientID, int Team)
@@ -608,7 +605,6 @@ void CGameTeams::OnFinish(CPlayer *Player, float Time, const char *pTimestamp)
 		if(g_Config.m_SvNamelessScore || !str_startswith(Server()->ClientName(ClientID), "nameless tee"))
 		{
 			GameServer()->m_pController->m_CurrentRecord = Time;
-			//dbg_msg("character", "Finish");
 			NeedToSendNewRecord = true;
 		}
 	}

src/game/server/teams.h

@@ -61,7 +61,8 @@ public:
 	void OnCharacterSpawn(int ClientID);
 	void OnCharacterDeath(int ClientID, int Weapon);
 
-	bool SetCharacterTeam(int ClientID, int Team);
+	// returns nullptr if successful, error string if failed
+	const char *SetCharacterTeam(int ClientID, int Team);
 	void CheckTeamFinished(int ClientID);
 
 	void ChangeTeamState(int Team, int State);