Junio C Hamano <gitster@xxxxxxxxx> writes:
> <rsbecker@xxxxxxxxxxxxx> writes:
>
>>>error: unknown option `cached'
>>>usage: git diff --no-index [<options>] <path> <path> [...]
>> ...
>> Because you are not in a git repository clone, the --cached option has no
>> meaning.
>
> Yes. "git diff" unfortunately has a mode where a limited subset of
> its features is available and that is called the "--no-index" mode.
>
> Because the command is capable of working outside a repository, "You
> are not in a repository" is a not a good error message in this
> situation, either. It is not that you stepped outside a repository
> that is your error. It is not that you used "--cached" that is your
> error, either. You used "--cached" outside a repository, that is
> where your error is.
>
> A patch to improve the error messages in such a situation is
> certainly welcome.
Having said that, there is already a warning() close by.
argc = parse_options(argc, argv, revs->prefix, options,
diff_no_index_usage, 0);
if (argc != 2) {
if (implicit_no_index)
warning(_("Not a git repository. Use --no-index to "
"compare two paths outside a working tree"));
usage_with_options(diff_no_index_usage, options);
}
and this gives
$ cd / && git diff foo 2>&1 | grep -e error: -e fatal: -e warning:
warning: Not a git repository. Use --no-index to compare two paths outside a working tree
a relevant warning.
But this is a bit too short to be effective for all failure modes.
parse_options() would die if it sees an invalid option. For that,
I suspect that we'd need to pass the usage string conditionally,
i.e.
argc = parse_options(argc, argv, revs->prefix, options,
implicit_no_index
? diff_no_index_usage_with_non_repo_warning
: diff_no_index_usage, 0);
with
static const char * const diff_no_index_usage_with_non_repo_warning[] = {
N_("git diff --no-index [<options>] <path> <path>"),
N_("Not in a git repository; some options may not make sense"),
NULL,
};
near where diff_no_index_usage[] is defined, or something silly like
that.
