Fix detector tube item counting

A detector tube would sometimes miss a decrement, due to the pos structure
passed to can_go being modified by the tubed-item entity while it's also
sitting in the timer queue as an argument to item_exit.  As the can_go
API actually depends on being able to mutate the pos structure (see the
teleporter tube), we can't just start passing in a never-mutated copy
of pos.  So for now just fix in the detector tube's can_go, by copying the
structure there.  Incidentally, make the decrement mechanism consistent
between the two forms of increment.

diff --git a/tubes.lua b/tubes.lua
index f8b3c5f7dfab40209237615b4134482951eba348..5e8a00976648f0c4c135a1f4e0c96ef4b8aab5a1 100644 (file)
--- a/tubes.lua
+++ b/tubes.lua
@@ -357,7 +357,6 @@ if pipeworks.enable_detector_tube then
        local detector_plain_textures = {"pipeworks_detector_tube_plain.png", "pipeworks_detector_tube_plain.png", "pipeworks_detector_tube_plain.png",
                                         "pipeworks_detector_tube_plain.png", "pipeworks_detector_tube_plain.png", "pipeworks_detector_tube_plain.png"}
        local detector_inv_texture = "pipeworks_detector_tube_inv.png"
-       local detector_tube_step = 2 * tonumber(minetest.setting_get("dedicated_server_step"))
        pipeworks.register_tube("pipeworks:detector_tube_on", "Detecting Pneumatic Tube Segment on (you hacker you)", detector_plain_textures, noctr_textures,
                                end_textures, short_texture, detector_inv_texture,
                                {tube = {can_go = function(pos, node, velocity, stack)
@@ -365,7 +364,12 @@ if pipeworks.enable_detector_tube then
                                                 local name = minetest.get_node(pos).name
                                                 local nitems = meta:get_int("nitems")+1
                                                 meta:set_int("nitems", nitems)
-                                                minetest.after(detector_tube_step, minetest.registered_nodes[name].item_exit, pos)
+                                                local saved_pos = { x = pos.x, y = pos.y, z = pos.z }
+                                                minetest.after(0, function ()
+                                                minetest.after(0, function ()
+                                                       minetest.after(0, minetest.registered_nodes[name].item_exit, saved_pos)
+                                                end)
+                                                end)
                                                 return pipeworks.notvel(pipeworks.meseadjlist,velocity)
                                        end},
                                 groups = {mesecon = 2, not_in_creative_inventory = 1},
@@ -389,9 +393,10 @@ if pipeworks.enable_detector_tube then
                                         local meta = minetest.get_meta(pos)
                                         meta:set_int("nitems", 1)
                                         local name = minetest.get_node(pos).name
+                                        local saved_pos = { x = pos.x, y = pos.y, z = pos.z }
                                         minetest.after(0, function ()
                                         minetest.after(0, function ()
-                                               minetest.after(0, minetest.registered_nodes[name].item_exit, pos)
+                                               minetest.after(0, minetest.registered_nodes[name].item_exit, saved_pos)
                                         end)
                                         end)
        end})