It starts as a NULL pointer, then might get set as a pointer to optarg,
then it might get set to point to an argv parameter, then it might have
a string value copied into it, over-writing the original data. We should
not risk over-writing internal variables which might get used for something
else (it's rude and security risk). Set up "when" as its own buffer
that has data from optargs and/or argv copied into it.
Minor code fixes across multiple source files to avoid buffer
overflows, or uninitialized strings.
