Add enable_pvp setting

minetest.conf.example

@@ -133,6 +133,8 @@
 #default_privs = build, shout
 # Whether players are transferred to client without any range limit
 #unlimited_player_transfer_distance = true
+# Whether to enable players killing each other
+#enable_pvp = true
 
 # Profiler data print interval. #0 = disable.
 #profiler_print_interval = 0

src/defaultsettings.cpp

@@ -94,6 +94,7 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("default_password", "");
 	settings->setDefault("default_privs", "build, shout");
 	settings->setDefault("unlimited_player_transfer_distance", "true");
+	settings->setDefault("enable_pvp", "true");
 
 	settings->setDefault("profiler_print_interval", "0");
 	settings->setDefault("enable_mapgen_debug_info", "false");

src/serverremoteplayer.cpp

@@ -139,6 +139,12 @@ void ServerRemotePlayer::punch(ServerActiveObject *puncher,
 	if(!puncher)
 		return;
 	
+	// No effect if PvP disabled
+	if(g_settings->getBool("enable_pvp") == false){
+		if(puncher->getType() == ACTIVEOBJECT_TYPE_PLAYER)
+			return;
+	}
+	
 	// "Material" properties of a player
 	MaterialProperties mp;
 	mp.diggability = DIGGABLE_NORMAL;