- Fuzzer error found when material access get's an out-of-bound access.
- Break parsing when material index gets out of range.
- closes https://github.com/assimp/assimp/issues/4232
std::string s(""); s = ""; calls the copy constructor, which in turn calls strlen(), … assigning a default-constructed string generates fewer instructions and is therefore preferred.
With C++11 uniform initialization, you’d simply write s = { } instead.
