The global buffer is 65536 bytes in size and not only 1 byte. This statement evaluated to a negative value which was casted to an unsigned value (aka... very large value).
This is a regression was introduced in 71dbc00fd879f1e592b07d8397f724fb3f69ac64 ("alfred: Use strncpy instead of strcpy for string").
Both patches applied of this series (c67658a, 71b36fa).
Thanks! Simon