SDL: Check for NULL before dereferencing newly allocated memory (d6910)

From d691010686550f19405a97ffce84eff7ebf6618c Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sun, 24 Sep 2023 17:17:49 -0700
Subject: [PATCH] Check for NULL before dereferencing newly allocated memory

Fixes https://github.com/libsdl-org/SDL/issues/8289

(cherry picked from commit 70a1bc69739016884a22abe6bf86f8a5deba29ef)
(cherry picked from commit 27f2df2292cceab64ff25f94efca5ec8bc5f1478)
---
 src/joystick/linux/SDL_sysjoystick.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/joystick/linux/SDL_sysjoystick.c b/src/joystick/linux/SDL_sysjoystick.c
index 479beb158442..4ba32ef35571 100644
--- a/src/joystick/linux/SDL_sysjoystick.c
+++ b/src/joystick/linux/SDL_sysjoystick.c
@@ -1752,11 +1752,11 @@ static SDL_bool LINUX_JoystickGetGamepadMapping(int device_index, SDL_GamepadMap
     /* We temporarily open the device to check how it's configured. Make
        a fake SDL_Joystick object to do so. */
     joystick = (SDL_Joystick *)SDL_calloc(sizeof(*joystick), 1);
-    joystick->magic = &SDL_joystick_magic;
     if (joystick == NULL) {
         SDL_OutOfMemory();
         return SDL_FALSE;
     }
+    joystick->magic = &SDL_joystick_magic;
     SDL_memcpy(&joystick->guid, &item->guid, sizeof(item->guid));
 
     joystick->hwdata = (struct joystick_hwdata *)