SDL: Make sure the string is terminated, fixed invalid read in SDL_PrivateParseGamepadConfigString()

From 312f98c2a1edaf9590fc06d10f201996c059d869 Mon Sep 17 00:00:00 2001
From: Sylvain <[EMAIL REDACTED]>
Date: Sat, 23 Dec 2023 21:30:09 +0100
Subject: [PATCH] Make sure the string is terminated, fixed invalid read in
 SDL_PrivateParseGamepadConfigString()

---
 src/joystick/SDL_gamepad.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/joystick/SDL_gamepad.c b/src/joystick/SDL_gamepad.c
index c911183da849..e1e5b89f03cc 100644
--- a/src/joystick/SDL_gamepad.c
+++ b/src/joystick/SDL_gamepad.c
@@ -1282,12 +1282,14 @@ static int SDL_PrivateParseGamepadConfigString(SDL_Gamepad *gamepad, const char
 
         } else if (bGameButton) {
             if (i >= sizeof(szGameButton)) {
+                szGameButton[sizeof(szGameButton) - 1] = '\0';
                 return SDL_SetError("Button name too large: %s", szGameButton);
             }
             szGameButton[i] = *pchPos;
             i++;
         } else {
             if (i >= sizeof(szJoystickButton)) {
+                szJoystickButton[sizeof(szJoystickButton) - 1] = '\0';
                 return SDL_SetError("Joystick button name too large: %s", szJoystickButton);
             }
             szJoystickButton[i] = *pchPos;