From 84a20b3f6180721c19d7fc5ebf1a54b11fb7fd54 Mon Sep 17 00:00:00 2001
From: bryanthaboi <bryanthaboi@theboisclub.com>
Date: Thu, 1 Oct 2026 11:56:12 -0400
Subject: [PATCH]  CLOSES #2603

---
 src/core/game3/battle_bridge.lua              |  2 +
 src/core/game3/party.lua                      |  1 +
 .../game3_evolve_ability_battle_2603.lua      | 88 +++++++++++++++++++
 3 files changed, 91 insertions(+)
 create mode 100644 tests/drivers/game3_evolve_ability_battle_2603.lua

diff --git a/src/core/game3/battle_bridge.lua b/src/core/game3/battle_bridge.lua
index e73f2acb..bad32e95 100644
--- a/src/core/game3/battle_bridge.lua
+++ b/src/core/game3/battle_bridge.lua
@@ -232,6 +232,8 @@ local function writeback(session, battleParty, remap, result, save, opts)
         speed = src.speed or src.spe,
         spAtk = src.spAtk or src.spa,
         spDef = src.spDef or src.spd,
+        ability = src.ability,
+        abilityId = src.abilityId,
         _allowMoveRewrite = true,
       })
       -- pokefirered/src/battle_controller_player.c:1909
diff --git a/src/core/game3/party.lua b/src/core/game3/party.lua
index c9c77572..d9e9661e 100644
--- a/src/core/game3/party.lua
+++ b/src/core/game3/party.lua
@@ -50,6 +50,7 @@ function Party.applyBattleFields(opaqueMon, fields)
     "species", "speciesId", "name", "growthRate",
     "attack", "defense", "speed", "spAtk", "spDef",
     "atk", "def", "spe", "spa", "spd", "ppBonusesPacked",
+    "ability", "abilityId",
   }) do
     if fields[key] ~= nil then opaqueMon[key] = fields[key] end
   end
diff --git a/tests/drivers/game3_evolve_ability_battle_2603.lua b/tests/drivers/game3_evolve_ability_battle_2603.lua
new file mode 100644
index 00000000..623e42d5
--- /dev/null
+++ b/tests/drivers/game3_evolve_ability_battle_2603.lua
@@ -0,0 +1,88 @@
+local U = require("tests.drivers.util")
+
+local MAGIKARP, GYARADOS = 129, 130
+local SWIFT_SWIM, INTIMIDATE = 33, 22
+
+local failures = 0
+local function result(ok, label)
+  print((ok and "PASS " or "FAIL ") .. label)
+  if not ok then failures = failures + 1 end
+  return ok
+end
+
+local function finish()
+  print(failures == 0 and "PASS evolve_ability_battle_2603" or ("FAIL evolve_ability_battle_2603 failures=" .. failures))
+  love.event.quit(failures == 0 and 0 or 1)
+  U.wait(10)
+end
+
+return function(game)
+  for _ = 1, 900 do
+    if game.phase == "boot" and game.boot then break end
+    U.wait(1)
+  end
+  game:_handleBootAction({ action = "new_game", name = "RED", gender = 0 })
+  U.wait(240)
+
+  local Runtime = require("src.core.game3.runtime")
+  local Party = require("src.core.game3.party")
+  local Pokemon = require("src.core.game3.pokemon")
+  local SummaryData = require("src.core.game3.summary_data")
+  local BattleBridge = require("src.core.game3.battle_bridge")
+  local Battle = require("src.core.game3.battle")
+  local Anim = require("src.core.game3.battle.anim")
+  local Ui = require("src.core.game3.battle.ui")
+  local Choice = require("src.ui.game3.choice")
+  local SummaryMenu = require("src.ui.game3.summary_menu")
+  local EvolutionScene = require("src.ui.game3.evolution_scene")
+
+  local session = Runtime.getSession()
+  if not result(session ~= nil, "field reached (" .. tostring(session and session.version) .. ")") then return finish() end
+  session.party = {}
+  Party.giveMon(session, MAGIKARP, 19)
+  local mine = session.party[1]
+  mine.moves = { 33, 0, 0, 0 }
+  mine.pp = { 35, 0, 0, 0 }
+  mine.maxPp = { 35, 0, 0, 0 }
+  mine.exp = SummaryData.expForLevel(Pokemon.growthRate(MAGIKARP), 20) - 1
+  result(mine.ability == SWIFT_SWIM, "Magikarp starts with Swift Swim (" .. tostring(mine.ability) .. ")")
+
+  local ok, err = BattleBridge.startWild(Runtime._mod, game, { species = MAGIKARP, level = 30 }, { fade = false })
+  if not result(ok == true, "battle started " .. tostring(err or "")) then return finish() end
+
+  local lastTap, f = 0, 0
+  for _ = 1, 20000 do
+    f = f + 1
+    local evoOpen = EvolutionScene.isOpen()
+    if not Battle.isActive() and not evoOpen then break end
+    if Battle.isActive() and Battle._phase == "command" and Ui._mode == "menu" then
+      local est = Battle.getState() and Battle.getState().enemy
+      if est and est.mon then
+        est.mon.moves = { 150, 0, 0, 0 }
+        est.mon.pp = { 40, 0, 0, 0 }
+        est.mon.hp = 1
+        local ep = Anim.present("enemy")
+        if ep then ep.displayHp = 1 end
+      end
+      Ui._pendingCommand = { kind = "move", move = 33, slot = 1, user = "player" }
+      Ui._mode = "none"
+      U.wait(2)
+    elseif Choice.active or SummaryMenu.isOpen() then
+      U.tap(game, "a")
+      U.wait(6)
+    elseif Anim.vm() and Anim.vm():busy() then
+      U.wait(1)
+    elseif f - lastTap >= 12 then
+      lastTap = f
+      U.tap(game, "a")
+    else
+      U.wait(1)
+    end
+  end
+  U.wait(30)
+  local mon = session.party[1]
+  result(Pokemon.speciesOf(mon) == GYARADOS, "post-battle evolution to Gyarados (" .. tostring(Pokemon.speciesOf(mon)) .. ")")
+  result(mon.ability == INTIMIDATE and mon.abilityId == INTIMIDATE,
+    "Gyarados has Intimidate (" .. tostring(mon.ability) .. "/" .. tostring(mon.abilityId) .. ")")
+  finish()
+end