Add `sv_coopsharekeys` - in coop, picking up a key will distribute it to all online players

src/d_main.cpp

@@ -573,6 +573,7 @@ CUSTOM_CVAR(Int, dmflags3, 0, CVAR_SERVERINFO | CVAR_NOINITCALL)
 }
 
 CVAR(Flag, sv_noplayerclip, dmflags3, DF3_NO_PLAYER_CLIP);
+CVAR(Flag, sv_coopsharekeys, dmflags3, DF3_COOP_SHARE_KEYS);
 
 //==========================================================================
 //

src/doomdef.h

@@ -180,6 +180,7 @@ enum : unsigned
 enum : unsigned
 {
 	DF3_NO_PLAYER_CLIP		= 1 << 0,	// Players can walk through and shoot through each other
+	DF3_COOP_SHARE_KEYS		= 1 << 1,	// Keys will be given to all players in coop
 };
 
 // [RH] Compatibility flags.

wadsrc/static/zscript/actors/inventory/inv_misc.zs

@@ -59,6 +59,28 @@ class Key : Inventory
 		return false;
 	}
 
+	override void AttachToOwner(Actor other)
+	{
+		Super.AttachToOwner(other);
+
+		if (multiplayer && !deathmatch && sv_coopsharekeys)
+		{
+			for (int i = 0; i < MAXPLAYERS; i++)
+			{
+				if (playeringame[i])
+				{
+					let pmo = players[i].mo;
+
+					if (pmo == other)
+						continue;
+
+					if (!pmo.FindInventory(GetClass()))
+						pmo.GiveInventoryType(GetClass());
+				}
+			}
+		}
+	}
+
 	override bool ShouldStay ()
 	{
 		return !!multiplayer;

wadsrc/static/zscript/actors/player/player.zs

@@ -888,7 +888,7 @@ class PlayerPawn : Actor
 			// inventory amount.
 			let defitem = FindInventory (item.GetClass());
 
-			if (sv_cooplosekeys && defitem == NULL && item is 'Key')
+			if ((sv_cooplosekeys && !sv_coopsharekeys) && defitem == NULL && item is 'Key')
 			{
 				item.Destroy();
 			}