From b818a7d776a7cbdd1118ea002639dde34f7aa64a Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Mon, 1 Apr 2024 18:03:00 +0100
Subject: [PATCH] Forbid character-based unlocks if you switched your skin in a
 context where it didn't auto-spectate you (more robust stop for #1231)

---
 src/d_netcmd.c | 45 ++++++++++++++++++++++++++-------------------
 src/d_player.h |  3 +++
 src/m_cond.c   |  8 ++++++--
 3 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/src/d_netcmd.c b/src/d_netcmd.c
index e821bcaab..78f88435c 100644
--- a/src/d_netcmd.c
+++ b/src/d_netcmd.c
@@ -1203,33 +1203,40 @@ static void Got_NameAndColor(const UINT8 **cp, INT32 playernum)
 
 		// The following is a miniature subset of Got_Teamchange.
 		if ((gamestate == GS_LEVEL) // In a level?
-			&& (cv_restrictskinchange.value) // Skin changes are restricted?
-			&& (G_GametypeHasSpectators() && players[playernum].spectator == false) // not a spectator but could be?
 			&& (players[playernum].jointime > 1) // permit on join
 			&& (leveltime > introtime) // permit during intro turnaround
 			&& (players[playernum].skin != oldskin)) // a skin change actually happened?
 		{
-			for (i = 0; i < MAXPLAYERS; ++i)
-			{
-				if (i == playernum)
-					continue;
-				if (!playeringame[i])
-					continue;
-				if (players[i].spectator)
-					continue;
-				break;
-			}
+			players[playernum].roundconditions.switched_skin = true;
 
-			if (i != MAXPLAYERS // Someone on your server who isn't you?
-				&& LUA_HookTeamSwitch(&players[playernum], 0, false, false, false)) // fiiiine, lua can except it
+			if (
+				cv_restrictskinchange.value // Skin changes are restricted?
+				&& G_GametypeHasSpectators() // not a spectator...
+				&& players[playernum].spectator == false // ...but could be?
+			)
 			{
-				P_DamageMobj(players[playernum].mo, NULL, NULL, 1, DMG_SPECTATOR);
-
-				if (players[i].spectator)
+				for (i = 0; i < MAXPLAYERS; ++i)
 				{
-					HU_AddChatText(va("\x82*%s became a spectator.", player_names[playernum]), false);
+					if (i == playernum)
+						continue;
+					if (!playeringame[i])
+						continue;
+					if (players[i].spectator)
+						continue;
+					break;
+				}
 
-					FinalisePlaystateChange(playernum);
+				if (i != MAXPLAYERS // Someone on your server who isn't you?
+					&& LUA_HookTeamSwitch(&players[playernum], 0, false, false, false)) // fiiiine, lua can except it
+				{
+					P_DamageMobj(players[playernum].mo, NULL, NULL, 1, DMG_SPECTATOR);
+
+					if (players[i].spectator)
+					{
+						HU_AddChatText(va("\x82*%s became a spectator.", player_names[playernum]), false);
+
+						FinalisePlaystateChange(playernum);
+					}
 				}
 			}
 		}
diff --git a/src/d_player.h b/src/d_player.h
index 9306af9cd..d0de6c444 100644
--- a/src/d_player.h
+++ b/src/d_player.h
@@ -464,6 +464,9 @@ struct roundconditions_t
 
 	// 32 triggers, one bit each, for map execution
 	UINT32 unlocktriggers;
+
+	// Forbidding skin-based unlocks if you changed your skin
+	boolean switched_skin;
 };
 
 // player_t struct for all skybox variables
diff --git a/src/m_cond.c b/src/m_cond.c
index 436db7dcf..010277a77 100644
--- a/src/m_cond.c
+++ b/src/m_cond.c
@@ -1649,9 +1649,13 @@ boolean M_CheckCondition(condition_t *cn, player_t *player)
 		case UCRP_ISMAP:
 			return (gamemap == cn->requirement+1);
 		case UCRP_ISCHARACTER:
-			return (player->skin == cn->requirement);
+			return (
+				player->roundconditions.switched_skin == false
+				&& player->skin == cn->requirement
+			);
 		case UCRP_ISENGINECLASS:
-			return (player->skin < numskins
+			return (player->roundconditions.switched_skin == false
+				&& player->skin < numskins
 				&& R_GetEngineClass(
 					skins[player->skin].kartspeed,
 					skins[player->skin].kartweight,