SDL: Fixed crash with a NULL serial number

SDL Commits
1 
From 18046b9aa3dabcc9bdc8d90c47c0721b25e032a1 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 26 Sep 2022 20:53:50 -0700
Subject: [PATCH] Fixed crash with a NULL serial number

---
 src/joystick/hidapi/SDL_hidapijoystick.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/joystick/hidapi/SDL_hidapijoystick.c b/src/joystick/hidapi/SDL_hidapijoystick.c
index e3db2cfc5d6..3fe935ef33f 100644
--- a/src/joystick/hidapi/SDL_hidapijoystick.c
+++ b/src/joystick/hidapi/SDL_hidapijoystick.c
@@ -534,6 +534,10 @@ HIDAPI_HasConnectedUSBDevice(const char *serial)
 {
     SDL_HIDAPI_Device *device;
 
+    if (!serial) {
+        return SDL_FALSE;
+    }
+
     for (device = SDL_HIDAPI_devices; device; device = device->next) {
         if (!device->driver) {
             continue;
@@ -555,6 +559,10 @@ HIDAPI_DisconnectBluetoothDevice(const char *serial)
 {
     SDL_HIDAPI_Device *device;
 
+    if (!serial) {
+        return;
+    }
+
     for (device = SDL_HIDAPI_devices; device; device = device->next) {
         if (!device->driver) {
             continue;