Jeff King [off-list ref] writes:
However, there is a good use for it: they should pass it to their own
parse_options() functions, where it may be used to adjust the value of
any filename options.
Oh, absolutely. Not passing prefix if they use OPT_FILENAME would
be a bug.
I'd emphasize that this wasn't broken by bf0a6b65fc; it has been broken
all along, because the sub-function never got to see the prefix. It is
that commit which is actually enabling us to fix it (and which also
brought attention to the problem because it triggers -Wunused-parameter!)
Yeah. I like that analysis. With the commit, we pass prefix
through the callgraph, and now we can fix it ;-)
Thanks.