fix(game3): gate the level-up stat window on the EXP sequence (#2324)

The FRLG level-up stat window opened and the sequence kept pumping, so the
box outlived its own step: it stopped taking input (routing is phase-gated),
never closed, and drew over the win/money text.

- exp_seq: update() now waits while the window is open (mirroring the
  already-correct busy()), and finish()/reset() tear the window down silently
  so a stale onDone cannot advance a sequence that no longer owns it.
- stat_growth: close(opts) gains opts.silent for teardown callers.
- init: the input-routing phase list moves into STAT_WINDOW_PHASES behind
  Battle.statWindowPhase(), and Battle.update() tears down a window whose
  phase can no longer dismiss it.
- ui: the stat-window draw keys off the same predicate, so input and drawing
  can never disagree.

Tests: the "In-Battle Level Up Stat Growth Window" block in
tests/game3_battle_switch_and_faint_test.lua now pumps ExpSeq.update() while
the box is open, and a new CI-covered tests/engine suite pins the same
regression.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

src/core/game3/battle/exp_seq.lua

@@ -7,6 +7,17 @@ local Pokemon = require("src.core.game3.pokemon")
 
 local ExpSeq = {}
 
+local function stat_growth()
+  local ok, SG = pcall(require, "src.ui.game3.stat_growth")
+  if ok and SG then return SG end
+  return nil
+end
+
+local function stat_window_open()
+  local SG = stat_growth()
+  return (SG and SG.isOpen and SG.isOpen()) and true or false
+end
+
 ExpSeq._steps = nil
 ExpSeq._i = 1
 ExpSeq._waiting = false
@@ -34,18 +45,13 @@ function ExpSeq.reset()
   if okA and okS and Audio.stopSe and SE and SE.SE_EXP then
     Audio.stopSe(SE.SE_EXP)
   end
-  local okSG, StatGrowth = pcall(require, "src.ui.game3.stat_growth")
-  if okSG and StatGrowth and StatGrowth.close then
-    StatGrowth.close()
-  end
+  local StatGrowth = stat_growth()
+  if StatGrowth and StatGrowth.close then StatGrowth.close({ silent = true }) end
   LearnMove.reset()
 end
 
 function ExpSeq.busy()
-  local okSG, StatGrowth = pcall(require, "src.ui.game3.stat_growth")
-  if okSG and StatGrowth and StatGrowth.isOpen and StatGrowth.isOpen() then
-    return true
-  end
+  if stat_window_open() then return true end
   return ExpSeq._steps ~= nil or LearnMove.busy()
 end
 
@@ -58,6 +64,10 @@ local function finish()
   ExpSeq._i = 1
   ExpSeq._waiting = false
   ExpSeq._waitingMsg = false
+  -- The step that owned the stat window is over; drop it without letting its
+  -- stale callback advance a sequence that has already ended (#2324).
+  local StatGrowth = stat_growth()
+  if StatGrowth and StatGrowth.close then StatGrowth.close({ silent = true }) end
   local okA, Audio = pcall(require, "src.core.game3.audio")
   local okS, SE = pcall(require, "src.core.game3.se_ids")
   if okA and okS and Audio.stopSe and SE and SE.SE_EXP then
@@ -334,6 +344,12 @@ function ExpSeq.update()
     if LearnMove.busy() then
       return false
     end
+    -- The level-up stat window waits for the player; its onDone callback clears
+    -- _waiting and advances.  Without this the sequence ran straight past the
+    -- open window, leaving it on screen (#2324).
+    if stat_window_open() then
+      return false
+    end
     if not Anim.busy() then
       advance()
     else

src/core/game3/battle/init.lua

@@ -44,6 +44,21 @@ Battle._residualStepState = nil
 
 local D = {}
 
+-- Phases in which the level-up stat window can still be dismissed by the
+-- player.  Input routing and drawing both key off this, so the window can never
+-- linger somewhere it can no longer be dismissed (#2324).
+local STAT_WINDOW_PHASES = {
+  awarding = true,
+  evolving = true,
+  switching = true,
+  shift_prompt = true,
+  catch_nickname_prompt = true,
+}
+
+function Battle.statWindowPhase()
+  return STAT_WINDOW_PHASES[Battle._phase] == true
+end
+
 -- pokefirered/src/battle_interface.c:2168
 local function hp_bar_red(hp, maxHp)
   local ok, BattleChrome = pcall(require, "src.ui.game3.battle_chrome")
@@ -2140,6 +2155,14 @@ Battle.finishCatchFlow = finish_catch_flow
 function Battle.update(dt, game)
   if not Battle._active then return end
 
+  -- A stat window whose phase can no longer dismiss it must not linger (#2324).
+  if not Battle.statWindowPhase() then
+    local StatGrowth = package.loaded["src.ui.game3.stat_growth"]
+    if StatGrowth and StatGrowth.isOpen and StatGrowth.isOpen() then
+      StatGrowth.close({ silent = true })
+    end
+  end
+
   local input = game and game.input
   local Pokedex = package.loaded["src.ui.game3.pokedex"]
   if Pokedex and Pokedex.isOpen and Pokedex.isOpen() then
@@ -2206,8 +2229,7 @@ function Battle.update(dt, game)
   end
 
   -- Choice input during award / shift prompt / evolution learn-move prompts / catch nickname prompt / evolving
-  if (Battle._phase == "awarding" or Battle._phase == "evolving" or Battle._phase == "switching"
-      or Battle._phase == "shift_prompt" or Battle._phase == "catch_nickname_prompt")
+  if Battle.statWindowPhase()
       and not Battle._auto and game and game.input then
     local EvolutionScene = package.loaded["src.ui.game3.evolution_scene"]
     if EvolutionScene and EvolutionScene.isOpen and EvolutionScene.isOpen() then

src/core/game3/battle/ui.lua

@@ -24,6 +24,15 @@ local BallOpen = require("src.core.game3.battle.ball_open")
 
 local Ui = {}
 
+-- The stat window may only be on screen while the battle is in a phase that can
+-- still dismiss it; init.lua owns the list (#2324).  Resolved lazily because
+-- init.lua requires this module.
+local function stat_window_phase()
+  local Battle = package.loaded["src.core.game3.battle.init"]
+  if not (Battle and Battle.statWindowPhase) then return true end
+  return Battle.statWindowPhase()
+end
+
 Ui._queue = {}
 Ui._showing = false
 Ui._headless = false
@@ -2032,7 +2041,8 @@ function Ui.draw(w, h)
   end
 
   local StatGrowth = package.loaded["src.ui.game3.stat_growth"]
-  if StatGrowth and StatGrowth.isOpen and StatGrowth.isOpen() and StatGrowth.draw then
+  if StatGrowth and StatGrowth.isOpen and StatGrowth.isOpen() and StatGrowth.draw
+      and stat_window_phase() then
     StatGrowth.draw()
   end
 

src/ui/game3/stat_growth.lua

@@ -39,7 +39,9 @@ function StatGrowth.isOpen()
   return StatGrowth._open
 end
 
-function StatGrowth.close()
+--- opts.silent drops the window without firing its onDone callback, for callers
+--- tearing down a step that no longer exists (#2324).
+function StatGrowth.close(opts)
   local wasOpen = StatGrowth._open
   StatGrowth._open = false
   StatGrowth._mon = nil
@@ -48,7 +50,7 @@ function StatGrowth.close()
   StatGrowth._page = 1
   local cb = StatGrowth._onDone
   StatGrowth._onDone = nil
-  if wasOpen and cb then cb() end
+  if wasOpen and cb and not (opts and opts.silent) then cb() end
 end
 
 function StatGrowth.handleInput(input)

tests/engine/battle_levelup_statwindow_bug2324.lua

@@ -0,0 +1,127 @@
+-- #2324: the level-up stat window gates the EXP sequence; it is never run past.
+--
+-- pokefirered draws the lvlup box from Cmd_drawlvlupbox and then *waits* for the
+-- player (battle_script_commands.c: Cmd_drawlvlupbox ends the command, the
+-- controller only returns after LvlUpBoxInput sees A/B).  The FRLG rewrite
+-- opened the box and kept pumping, so the box outlived its own step: it could
+-- no longer be dismissed (input routing is phase-gated) and sat on screen over
+-- the win/money text.
+--
+--   luajit tests/engine/battle_levelup_statwindow_bug2324.lua
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.modkit")
+local check, eq = T.check, T.eq
+
+local Experience = require("src.core.game3.battle.experience")
+local ExpSeq = require("src.core.game3.battle.exp_seq")
+local StatGrowth = require("src.ui.game3.stat_growth")
+local Ui = require("src.core.game3.battle.ui")
+local Anim = require("src.core.game3.battle.anim")
+local Battle = require("src.core.game3.battle.init")
+
+local A_PRESS = { wasPressed = function(_, key) return key == "a" end }
+local NO_PRESS = { wasPressed = function() return false end }
+
+-- A mon one award away from a level, so the sequence always grows stats.
+local function levelUpMon()
+  return {
+    species = 1,
+    level = 5,
+    hp = 20,
+    maxHp = 20,
+    attack = 10,
+    defense = 10,
+    spAtk = 12,
+    spDef = 12,
+    speed = 9,
+    exp = Experience.expForLevel(3, 5),
+    growthRate = 3,
+  }
+end
+
+--- Runs the sequence up to the point the stat window opens.
+--- Returns the pushMsg log and the ExpSeq step index at that moment.
+local function pumpToStatWindow()
+  local mon = levelUpMon()
+  local res = Experience.apply(mon, 100)
+  local messages = {}
+  local awards = { { mon = mon, result = res, partyIndex = 1 } }
+
+  Ui.reset({ headless = false })
+  check(ExpSeq.begin(awards, function(t) messages[#messages + 1] = t end, nil,
+    { headless = false }), "the level-up award starts an EXP sequence")
+
+  -- exp-gain text, then the bar, then the grew-to-LV text
+  for _ = 1, 4 do
+    ExpSeq.update()
+    Ui._showing = false
+    Ui._queue = {}
+    Anim.reset({ headless = false })
+  end
+
+  check(StatGrowth.isOpen(), "the stat window opened on level up")
+  eq(StatGrowth._page, 1, "the stat window starts on Page 1 (diffs)")
+  return messages, ExpSeq._i, mon, res
+end
+
+do
+  local messages, stepBefore = pumpToStatWindow()
+  local msgsBefore = #messages
+
+  -- The box waits for the player: idle pumps must not move the sequence.
+  for i = 1, 20 do
+    eq(ExpSeq.update(), false, "pump " .. i .. " reports busy while the box is open")
+  end
+  eq(ExpSeq._i, stepBefore, "idle pumps did not advance the sequence")
+  eq(#messages, msgsBefore, "idle pumps pushed no further battle text")
+  check(StatGrowth.isOpen(), "the box is still open after 20 idle pumps")
+  eq(StatGrowth._page, 1, "the box is still on Page 1 after 20 idle pumps")
+
+  -- Page 2 is still a wait.
+  check(StatGrowth.handleInput(A_PRESS), "A consumed on Page 1")
+  eq(StatGrowth._page, 2, "the box flipped to Page 2 (new values)")
+  check(StatGrowth.isOpen(), "the box is still open on Page 2")
+  for _ = 1, 20 do
+    eq(ExpSeq.update(), false, "pump reports busy while Page 2 is open")
+  end
+  eq(ExpSeq._i, stepBefore, "Page 2 idle pumps did not advance the sequence")
+  eq(#messages, msgsBefore, "Page 2 idle pumps pushed no further battle text")
+
+  -- The second A press is what releases the sequence.
+  check(StatGrowth.handleInput(A_PRESS), "A consumed on Page 2")
+  check(not StatGrowth.isOpen(), "the second A press closed the box")
+  eq(ExpSeq._i, stepBefore + 1, "the sequence advanced only once the box closed")
+
+  -- And it can be driven to the end from there without the box coming back.
+  local guard = 0
+  while not ExpSeq.update() and guard < 200 do
+    guard = guard + 1
+    Ui._showing = false
+    Ui._queue = {}
+    Anim.reset({ headless = false })
+  end
+  check(guard < 200, "the sequence finishes after the box is dismissed")
+  check(not StatGrowth.isOpen(), "no stat window survives the finished sequence")
+  check(ExpSeq.busy() == false, "ExpSeq.busy() is false once the sequence is done")
+end
+
+do
+  -- A box whose phase can no longer dismiss it must not linger: input routing is
+  -- phase-gated, so a box left open outside those phases would be undismissable
+  -- and would draw over the win/money text.
+  local _, _, mon, res = pumpToStatWindow()
+
+  local savedActive, savedPhase, savedHeadless = Battle._active, Battle._phase, Battle._headless
+  Battle._active, Battle._phase, Battle._headless = true, nil, true
+  StatGrowth.open(mon, res.steps[1].oldStats, res.steps[1].newStats, function()
+    error("a torn-down stat window must not fire its onDone callback")
+  end)
+  check(StatGrowth.isOpen(), "a stale box is open before Battle.update")
+  Battle.update(1 / 60, { input = NO_PRESS })
+  check(not StatGrowth.isOpen(), "Battle.update tears down a box outside its phases")
+  Battle._active, Battle._phase, Battle._headless = savedActive, savedPhase, savedHeadless
+end
+
+T.finish("battle_levelup_statwindow_bug2324")

tests/game3_battle_switch_and_faint_test.lua

@@ -568,6 +568,17 @@ do
   check(StatGrowth.isOpen(), "StatGrowth window opened on level up")
   eq(StatGrowth._page, 1, "StatGrowth starts on Page 1 (diffs)")
 
+  -- #2324: the sequence must WAIT on the window, not run past it.
+  local stepBefore = ExpSeq._i
+  local msgsBefore = #messages
+  for _ = 1, 20 do
+    eq(ExpSeq.update(), false, "ExpSeq.update() reports busy while the stat window is open")
+  end
+  eq(ExpSeq._i, stepBefore, "ExpSeq did not advance past the open stat window")
+  eq(#messages, msgsBefore, "no battle text pushed while the stat window is open")
+  check(StatGrowth.isOpen(), "StatGrowth still open after idle pumps")
+  eq(StatGrowth._page, 1, "StatGrowth still on Page 1 after idle pumps")
+
   -- Advance to Page 2
   local fakeInput = {
     wasPressed = function(self, key) return key == "a" end,
@@ -576,9 +587,29 @@ do
   check(StatGrowth.isOpen(), "StatGrowth still open on Page 2")
   eq(StatGrowth._page, 2, "StatGrowth on Page 2 (new values)")
 
+  -- #2324: Page 2 is still a wait
+  for _ = 1, 20 do
+    eq(ExpSeq.update(), false, "ExpSeq.update() reports busy on stat window Page 2")
+  end
+  eq(ExpSeq._i, stepBefore, "ExpSeq still did not advance on Page 2")
+  check(StatGrowth.isOpen(), "StatGrowth still open after idle pumps on Page 2")
+  eq(#messages, msgsBefore, "still no battle text while Page 2 is up")
+
   -- Confirm Page 2 -> closes window and advances sequence
   StatGrowth.handleInput(fakeInput)
   check(not StatGrowth.isOpen(), "StatGrowth closed after confirmation")
+  eq(ExpSeq._i, stepBefore + 1, "ExpSeq advanced only once the window closed")
+
+  -- #2324: a window whose phase can no longer dismiss it must be torn down.
+  local savedActive, savedPhase, savedHeadless = Battle._active, Battle._phase, Battle._headless
+  Battle._active, Battle._phase, Battle._headless = true, nil, true
+  StatGrowth.open(mon, res.steps[1].oldStats, res.steps[1].newStats, function()
+    error("[FAIL] a torn-down stat window must not fire its onDone callback")
+  end)
+  check(StatGrowth.isOpen(), "stale stat window open before Battle.update")
+  Battle.update(1 / 60, { input = fakeInput })
+  check(not StatGrowth.isOpen(), "Battle.update closed a stat window outside its phases")
+  Battle._active, Battle._phase, Battle._headless = savedActive, savedPhase, savedHeadless
 end
 
 print("\nALL BATTLE SWITCH & FAINT TESTS PASSED! (100%)")