GeezerVison

Account for NUL terminators in fallback getnameinfo. On systems without a native getnameinfo(), the fallback checks whether a host or service string fits but does not reserve space for the terminating NUL written by strcpy. If the string length exactly equals the output buffer capacity, the terminator is written one byte past the end, potentially corrupting adjacent memory. Reject equal lengths as well as longer strings.

Backport to 3.15 and 3.14.

• Issue: Fix minor safety issues #159739