Fixed crash if manufacturer or product string is NULL

src/joystick/hidapi/SDL_hidapijoystick.c

@@ -699,15 +699,27 @@ HIDAPI_AddDevice(struct hid_device_info *info)
 
     /* Need the device name before getting the driver to know whether to ignore this device */
     {
-        char *manufacturer_string = SDL_iconv_string("UTF-8", "WCHAR_T", (char*)info->manufacturer_string, (SDL_wcslen(info->manufacturer_string)+1)*sizeof(wchar_t));
-        char *product_string = SDL_iconv_string("UTF-8", "WCHAR_T", (char*)info->product_string, (SDL_wcslen(info->product_string)+1)*sizeof(wchar_t));
-        if (!manufacturer_string && !product_string) {
-            if (sizeof(wchar_t) == sizeof(Uint16)) {
-                manufacturer_string = SDL_iconv_string("UTF-8", "UCS-2-INTERNAL", (char*)info->manufacturer_string, (SDL_wcslen(info->manufacturer_string)+1)*sizeof(wchar_t));
-                product_string = SDL_iconv_string("UTF-8", "UCS-2-INTERNAL", (char*)info->product_string, (SDL_wcslen(info->product_string)+1)*sizeof(wchar_t));
-            } else if (sizeof(wchar_t) == sizeof(Uint32)) {
-                manufacturer_string = SDL_iconv_string("UTF-8", "UCS-4-INTERNAL", (char*)info->manufacturer_string, (SDL_wcslen(info->manufacturer_string)+1)*sizeof(wchar_t));
-                product_string = SDL_iconv_string("UTF-8", "UCS-4-INTERNAL", (char*)info->product_string, (SDL_wcslen(info->product_string)+1)*sizeof(wchar_t));
+        char *manufacturer_string = NULL;
+        char *product_string = NULL;
+
+        if (info->manufacturer_string) {
+            manufacturer_string = SDL_iconv_string("UTF-8", "WCHAR_T", (char*)info->manufacturer_string, (SDL_wcslen(info->manufacturer_string)+1)*sizeof(wchar_t));
+            if (!manufacturer_string) {
+                if (sizeof(wchar_t) == sizeof(Uint16)) {
+                    manufacturer_string = SDL_iconv_string("UTF-8", "UCS-2-INTERNAL", (char*)info->manufacturer_string, (SDL_wcslen(info->manufacturer_string)+1)*sizeof(wchar_t));
+                } else if (sizeof(wchar_t) == sizeof(Uint32)) {
+                    manufacturer_string = SDL_iconv_string("UTF-8", "UCS-4-INTERNAL", (char*)info->manufacturer_string, (SDL_wcslen(info->manufacturer_string)+1)*sizeof(wchar_t));
+                }
+            }
+        }
+        if (info->product_string) {
+            product_string = SDL_iconv_string("UTF-8", "WCHAR_T", (char*)info->product_string, (SDL_wcslen(info->product_string)+1)*sizeof(wchar_t));
+            if (!product_string) {
+                if (sizeof(wchar_t) == sizeof(Uint16)) {
+                    product_string = SDL_iconv_string("UTF-8", "UCS-2-INTERNAL", (char*)info->product_string, (SDL_wcslen(info->product_string)+1)*sizeof(wchar_t));
+                } else if (sizeof(wchar_t) == sizeof(Uint32)) {
+                    product_string = SDL_iconv_string("UTF-8", "UCS-4-INTERNAL", (char*)info->product_string, (SDL_wcslen(info->product_string)+1)*sizeof(wchar_t));
+                }
             }
         }