fix(input): ignore raw face presses when Joy-Con is gamepad

love-nx emits gamepad+raw on one press; NamingScreen saw a+b and always
erased. Skip raw when isGamepad(); align NX Y→a/X→b; prefer A if both.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/core/GamepadMap.lua

@@ -16,11 +16,13 @@ GamepadMap.RAW_BUTTON_BINDINGS = {
   [7] = "select", [8] = "start", [9] = "select", [10] = "start",
 }
 
--- Switch OLED probe 2026-08-01: love.joystickpressed indices (1-based).
--- Gamepad path still preferred when isGamepad(); raw covers the rest.
+-- Switch OLED: love.joystickpressed indices (1-based). Used only when the
+-- device is NOT a gamepad — love-nx also emits gamepadpressed for Joy-Con,
+-- and applying both face paths in one frame breaks NamingScreen (a+b).
+-- Y→a / X→b matches operator OLED naming diagnosis (2026-08-01).
 GamepadMap.NX_RAW_BUTTON_BINDINGS = {
   [1] = "a", [2] = "b",
-  [3] = "b", [4] = "a",
+  [3] = "a", [4] = "b",
   [9] = "select", [10] = "start",
 }
 
@@ -32,7 +34,7 @@ GamepadMap.RAW_TO_GAMEPAD_BUTTON = {
 
 GamepadMap.NX_RAW_TO_GAMEPAD_BUTTON = {
   [1] = "a", [2] = "b",
-  [3] = "y", [4] = "x",
+  [3] = "a", [4] = "b",
   [9] = "back", [10] = "start",
 }
 
@@ -54,6 +56,16 @@ function GamepadMap.mapGamepadButton(button)
   return GamepadMap.DEFAULT_GAMEPAD_BINDINGS[button]
 end
 
+-- love-nx / SDL: when isGamepad(), face+menu already arrive via gamepad*.
+-- Applying joystickpressed raw on top double-fires GB A/B in one frame.
+function GamepadMap.ignoreRawForJoystick(joystick)
+  if not joystick then return false end
+  local ok, isPad = pcall(function()
+    return joystick.isGamepad and joystick:isGamepad()
+  end)
+  return ok and isPad == true
+end
+
 function GamepadMap.mapRawButton(index)
   if nxActive() then
     local nx = GamepadMap.NX_RAW_BUTTON_BINDINGS[index]

src/core/Input.lua

@@ -180,11 +180,13 @@ function Input:gamepadreleased(joystick, button)
 end
 
 function Input:joystickpressed(joystick, button)
+  if GamepadMap.ignoreRawForJoystick(joystick) then return end
   local btn = GamepadMap.mapRawButton(button)
   if btn then press(self, btn, "joy:" .. button) end
 end
 
 function Input:joystickreleased(joystick, button)
+  if GamepadMap.ignoreRawForJoystick(joystick) then return end
   local btn = GamepadMap.mapRawButton(button)
   if btn then release(self, btn, "joy:" .. button) end
 end

src/import/RomImporter.lua

@@ -1548,11 +1548,13 @@ function RomImporter:gamepadaxis(_, axis, value)
 end
 
 function RomImporter:joystickpressed(joystick, button)
+  if GamepadMap.ignoreRawForJoystick(joystick) then return end
   local padButton = GamepadMap.mapRawToGamepadButton(button)
   if padButton then self:gamepadpressed(joystick, padButton) end
 end
 
 function RomImporter:joystickreleased(joystick, button)
+  if GamepadMap.ignoreRawForJoystick(joystick) then return end
   local padButton = GamepadMap.mapRawToGamepadButton(button)
   if padButton then self:gamepadreleased(joystick, padButton) end
 end

src/ui/NamingScreen.lua

@@ -153,9 +153,15 @@ function NamingScreen:update(dt)
     if self.row ~= caseRow then
       self.col = self.col < #GRID[self.row] and self.col + 1 or 1
     end
-  elseif input:wasPressed("b") then
+  else
+    -- Prefer A over B when both edges fire in one frame (love-nx dual
+    -- gamepad+raw path historically set both; erase must not win).
+    local pressedA = input:wasPressed("a")
+    local pressedB = input:wasPressed("b")
+    if pressedA and pressedB then pressedB = false end
+    if pressedB then
       table.remove(self.glyphs)
-  elseif input:wasPressed("a") then
+    elseif pressedA then
       if self.row == edRow and self.col == edCol then
         self:confirm()
         return
@@ -171,6 +177,7 @@ function NamingScreen:update(dt)
       end
     end
   end
+end
 
 function NamingScreen:draw()
   love.graphics.setColor(1, 1, 1, 1)

tests/engine/input_dual_path_test.lua

@@ -0,0 +1,42 @@
+-- When isGamepad(), raw face presses must not stack on gamepad* (NamingScreen a+b).
+package.path = "./?.lua;./?/init.lua;" .. package.path
+if not _G.love then _G.love = require("tests.love_stub") end
+
+local T = require("tests.harness")
+local check = T.check
+local eq = T.eq
+
+local GamepadMap = require("src.core.GamepadMap")
+local Input = require("src.core.Input")
+
+local gamepadJoy = {
+  isGamepad = function() return true end,
+}
+local rawJoy = {
+  isGamepad = function() return false end,
+}
+
+check(GamepadMap.ignoreRawForJoystick(gamepadJoy), "ignore raw when isGamepad")
+check(not GamepadMap.ignoreRawForJoystick(rawJoy), "allow raw when not gamepad")
+check(not GamepadMap.ignoreRawForJoystick(nil), "nil joystick does not ignore raw")
+
+GamepadMap._setForceNXForTests(true)
+eq(GamepadMap.mapRawButton(3), "a", "NX raw Y (#3) -> GB A")
+eq(GamepadMap.mapRawButton(4), "b", "NX raw X (#4) -> GB B")
+GamepadMap._setForceNXForTests(false)
+
+Input:init()
+Input:gamepadpressed(gamepadJoy, "a")
+Input:joystickpressed(gamepadJoy, 1) -- must no-op
+Input:joystickpressed(gamepadJoy, 2) -- must no-op (would have set b)
+Input:step()
+check(Input:wasPressed("a"), "gamepad A edge present")
+check(not Input:wasPressed("b"), "raw must not add B alongside gamepad A")
+check(Input:isDown("a"), "A held from pad source only")
+
+Input:init()
+Input:joystickpressed(rawJoy, 1)
+Input:step()
+check(Input:wasPressed("a"), "non-gamepad raw #1 still maps to A")
+
+T.finish()

tests/engine/input_nx_raw_map_test.lua

@@ -9,11 +9,11 @@ local GamepadMap = require("src.core.GamepadMap")
 
 GamepadMap._setForceNXForTests(true)
 
--- Phase 0 probe: Y→#3, X→#4; Nintendo B/A at #1/#2.
-eq(GamepadMap.mapRawButton(3), "b", "NX raw Y (#3) maps to GB B")
-eq(GamepadMap.mapRawButton(4), "a", "NX raw X (#4) maps to GB A")
-eq(GamepadMap.mapRawToGamepadButton(3), "y", "NX raw #3 routes to gamepad y")
-eq(GamepadMap.mapRawToGamepadButton(4), "x", "NX raw #4 routes to gamepad x")
+-- Phase 0 / naming diagnosis: Y→#3→a, X→#4→b; Nintendo B/A at #1/#2.
+eq(GamepadMap.mapRawButton(3), "a", "NX raw Y (#3) maps to GB A")
+eq(GamepadMap.mapRawButton(4), "b", "NX raw X (#4) maps to GB B")
+eq(GamepadMap.mapRawToGamepadButton(3), "a", "NX raw #3 routes to gamepad a")
+eq(GamepadMap.mapRawToGamepadButton(4), "b", "NX raw #4 routes to gamepad b")
 eq(GamepadMap.mapRawButton(9), "select", "NX minus (#9) -> select")
 eq(GamepadMap.mapRawButton(10), "start", "NX plus (#10) -> start")