From 59602fb4732c8ab6f3e0a9d94d7fb8e34f1f79f8 Mon Sep 17 00:00:00 2001
From: foxtacles <[EMAIL REDACTED]>
Date: Fri, 3 Apr 2026 15:07:50 -0700
Subject: [PATCH] (emscripten) Add null checks for gamepad in
vendor/product/xinput helpers (#15313)
navigator.getGamepads() can return null for a slot if the gamepad
disconnects between the gamepadconnected event and the proxied
MAIN_THREAD_EM_ASM_INT call. This causes a TypeError when accessing
gamepad.id. Add null guards matching the pattern already used in
EMSCRIPTEN_JoystickOpen and EMSCRIPTEN_JoystickRumble.
---
src/joystick/emscripten/SDL_sysjoystick.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/src/joystick/emscripten/SDL_sysjoystick.c b/src/joystick/emscripten/SDL_sysjoystick.c
index 156917e682380..5d831bddbba42 100644
--- a/src/joystick/emscripten/SDL_sysjoystick.c
+++ b/src/joystick/emscripten/SDL_sysjoystick.c
@@ -37,9 +37,11 @@ static int numjoysticks = 0;
static int SDL_GetEmscriptenJoystickVendor(int device_index)
{
- // Let's assume that if we're calling these function then the gamepad object definitely exists
return MAIN_THREAD_EM_ASM_INT({
let gamepad = navigator['getGamepads']()[$0];
+ if (!gamepad) {
+ return 0;
+ }
// Chrome, Edge, Opera: Wireless Controller (STANDARD GAMEPAD Vendor: 054c Product: 09cc)
let vendor_str = 'Vendor: ';
@@ -62,6 +64,9 @@ static int SDL_GetEmscriptenJoystickProduct(int device_index)
{
return MAIN_THREAD_EM_ASM_INT({
let gamepad = navigator['getGamepads']()[$0];
+ if (!gamepad) {
+ return 0;
+ }
// Chrome, Edge, Opera: Wireless Controller (STANDARD GAMEPAD Vendor: 054c Product: 09cc)
let product_str = 'Product: ';
@@ -84,6 +89,9 @@ static int SDL_IsEmscriptenJoystickXInput(int device_index)
{
return MAIN_THREAD_EM_ASM_INT({
let gamepad = navigator['getGamepads']()[$0];
+ if (!gamepad) {
+ return 0;
+ }
// Chrome, Edge, Opera: Xbox 360 Controller (XInput STANDARD GAMEPAD)
// Firefox: xinput