Re: [PATCH v3 2/4] cat-file: introduce the --filters option

[Junio C Hamano <gitster@pobox.com>]

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

>> > +	if (type != OBJ_BLOB) {
>> > +		free(*buf);
>> > +		return error(_("blob expected for %s '%s'"),
>> > +			sha1_to_hex(sha1), path);
>> > +	}
>> > +	if (S_ISREG(mode)) {
>> > +		struct strbuf strbuf = STRBUF_INIT;
>> > +		if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
>> > +			free(*buf);
>> > +			*size = strbuf.len;
>> > +			*buf = strbuf_detach(&strbuf, NULL);
>> > +		}
>> > +	}
>> 
>> This needs to error out when mode is not ISREG just like it errors
>> out when type is not BLOB.
>
> Are you sure that this is desirable in batch mode?

I do not quite see a reason why we should not diagnose a bad input
that does not produce a filtered result.  In batch mode or not, it
diagnoses when the user feeds it a non-blob, and I think it should
do so for non-regular, too. Both are "you asked me to filter, but
you shouldn't have".