Read ammo slots on join so the first shot is logged

Clearing the slots on leave meant nothing was known about a player's ammo
until it changed, so the first shot after rejoining was missed. The slots
are now read when a player joins and when they respawn, since a new
character starts empty and a stale single round would otherwise count as
a shot. The change handler reads the slots the same way and compares them
with what was stored.

exp_scenario/module/control/deconstruction_log.lua

@@ -148,34 +148,42 @@ Storage.register(ammo_slots, function(tbl)
     ammo_slots = tbl
 end)
 
---- Log a shot, there is no fired event so a slot losing one of the same ammo is taken as a shot
---- @param event EventData.on_player_ammo_inventory_changed
-local function on_player_ammo_inventory_changed(event)
-    local player = get_log_player(event)
-    if not player or not player.character then return end
-
-    local slots = ammo_slots[player.index]
-    if not slots then
-        slots = {}
-        ammo_slots[player.index] = slots
-    end
+--- Read the ammo slots of a player, empty while they have no character
+--- @param player LuaPlayer
+--- @return table<uint, ExpScenario_DeconstructionLog.AmmoSlot>
+local function read_ammo_slots(player)
+    local slots = {}
+    if not player.character then return slots end
 
     local character_ammo = assert(player.get_inventory(defines.inventory.character_ammo))
     for index = 1, #character_ammo do
         local stack = character_ammo[index --[[@as uint]]]
-        local previous = slots[index]
-        local fired = nil --- @type string?
-
         if stack.valid_for_read then
-            if previous and previous.name == stack.name and previous.count == stack.count + 1 then
-                fired = stack.name
-            end
             slots[index] = { name = stack.name, count = stack.count }
-        else
-            if previous and previous.count == 1 then
-                fired = previous.name
         end
-            slots[index] = nil
+    end
+    return slots
+end
+
+--- Log a shot, there is no fired event so a slot losing one of the same ammo is taken as a shot
+--- @param event EventData.on_player_ammo_inventory_changed
+local function on_player_ammo_inventory_changed(event)
+    local player = get_log_player(event)
+    if not player then return end
+
+    local previous_slots = ammo_slots[player.index] or {}
+    local slots = read_ammo_slots(player)
+    ammo_slots[player.index] = slots
+
+    for index, previous in pairs(previous_slots) do
+        local current = slots[index]
+        local fired = nil --- @type string?
+        if current then
+            if previous.name == current.name and previous.count == current.count + 1 then
+                fired = current.name
+            end
+        elseif previous.count == 1 then
+            fired = previous.name
         end
 
         if fired and logged_ammo[fired] then
@@ -184,13 +192,19 @@ local function on_player_ammo_inventory_changed(event)
     end
 end
 
---- Forget the ammo of a player who left, their slots are read again on the next change
+--- Read the ammo of a player when they join or get a new character, so the first shot afterwards is seen
+--- @param event EventData.on_player_joined_game | EventData.on_player_respawned
+local function on_player_character_changed(event)
+    local player = assert(game.get_player(event.player_index))
+    ammo_slots[player.index] = read_ammo_slots(player)
+end
+
+--- Forget the ammo of a player who left
 --- @param event EventData.on_player_left_game
 local function on_player_left_game(event)
     ammo_slots[event.player_index] = nil
 end
 
-
 local e = defines.events
 local events = {
     [e.on_multiplayer_init] = clear_log,
@@ -210,6 +224,8 @@ end
 
 if config.fired_rocket or config.fired_explosive_rocket or config.fired_nuke then
     events[e.on_player_ammo_inventory_changed] = on_player_ammo_inventory_changed
+    events[e.on_player_joined_game] = on_player_character_changed
+    events[e.on_player_respawned] = on_player_character_changed
     events[e.on_player_left_game] = on_player_left_game
 end