Add coop_pickup_weapons, allow a weapon to be taken several times.

In coop a weapon can be picked up only once. That's annoying, because in
coop ammunition is sparse and not getting the ammunition that comes with
a weapons make things worse. When `coop_pickup_weapons` is set to `1` a
weapon may be picked up if:

1) The player doesn't have the weapon in their inventory.
2) No other player has already picked it up.

doc/040_cvarlist.md

@@ -113,6 +113,14 @@ it's `+set busywait 0` (setting the `busywait` cvar) and `-portable`
   spawned in maps (in fact, some official Ground Zero maps contain
   these entities). This cvar is set to 0 by default.
 
+* **coop_pickup_weapons**: In coop a weapon can be picked up only once.
+  For example, if the player already has the shotgun they cannot pickup
+  a second shotgun found at a later time, thus not getting the ammo that
+  comes with it. This breaks the balacing. If set to `1` a weapon can be
+  picked up if a) the player doesn't have it or b) it wasn't already
+  picked up by another player. Defaults to `0`.
+
+
 ## Audio
 
 * **al_device**: OpenAL device to use. In most cases there's no need to

src/game/g_main.c

@@ -40,6 +40,7 @@ edict_t *g_edicts;
 
 cvar_t *deathmatch;
 cvar_t *coop;
+cvar_t *coop_pickup_weapons;
 cvar_t *dmflags;
 cvar_t *skill;
 cvar_t *fraglimit;

src/game/header/local.h

@@ -72,6 +72,7 @@
 #define FL_TEAMSLAVE 0x00000400 /* not the first on the team */
 #define FL_NO_KNOCKBACK 0x00000800
 #define FL_POWER_ARMOR 0x00001000 /* power armor (if any) is active */
+#define FL_COOP_TAKEN 0x00002000 /* Another client has already taken it */
 #define FL_RESPAWN 0x80000000 /* used for item respawning */
 
 #define FRAMETIME 0.1
@@ -507,6 +508,7 @@ extern edict_t *g_edicts;
 extern cvar_t *maxentities;
 extern cvar_t *deathmatch;
 extern cvar_t *coop;
+extern cvar_t *coop_pickup_weapons;
 extern cvar_t *dmflags;
 extern cvar_t *skill;
 extern cvar_t *fraglimit;

src/game/player/weapon.c

@@ -184,7 +184,8 @@ Pickup_Weapon(edict_t *ent, edict_t *other)
 	if ((((int)(dmflags->value) & DF_WEAPONS_STAY) || coop->value) &&
 		other->client->pers.inventory[index])
 	{
-		if (!(ent->spawnflags & (DROPPED_ITEM | DROPPED_PLAYER_ITEM)))
+		if (!(ent->spawnflags & (DROPPED_ITEM | DROPPED_PLAYER_ITEM)) &&
+				(!coop_pickup_weapons->value || (ent->flags & FL_COOP_TAKEN)))
 		{
 			return false; /* leave the weapon for others to pickup */
 		}
@@ -223,14 +224,14 @@ Pickup_Weapon(edict_t *ent, edict_t *other)
 			if (coop->value)
 			{
 				ent->flags |= FL_RESPAWN;
+				ent->flags |= FL_COOP_TAKEN;
 			}
 		}
 	}
 
 	if ((other->client->pers.weapon != ent->item) &&
 		(other->client->pers.inventory[index] == 1) &&
-		(!deathmatch->value ||
-		 (other->client->pers.weapon == FindItem("blaster"))))
+		(!deathmatch->value || (other->client->pers.weapon == FindItem("blaster"))))
 	{
 		other->client->newweapon = ent->item;
 	}

src/game/savegame/savegame.c

@@ -232,6 +232,7 @@ InitGame(void)
 	maxspectators = gi.cvar("maxspectators", "4", CVAR_SERVERINFO);
 	deathmatch = gi.cvar("deathmatch", "0", CVAR_LATCH);
 	coop = gi.cvar("coop", "0", CVAR_LATCH);
+	coop_pickup_weapons = gi.cvar("coop_pickup_weapons", "0", 0);
 	skill = gi.cvar("skill", "1", CVAR_LATCH);
 	maxentities = gi.cvar("maxentities", "1024", CVAR_LATCH);