Disregarding some 3rd-party utility library's private (non-standard) conventions, all strings in C are null-terminated.

If you did't find the trailing 0, then either you're not at the end yet, or else it's the provider's bug upstream sending you a defective malformed "string", as in, you segfaulted by reading beyond your given memory without finding it.

This was me, it is my old solution, and it is shameful. The fact that it gathered some votes is shameful and seems closely related to the disaster we are in.