Re: [PATCH 2/6] quote_path: give flags parameter to quote_path()

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

Junio C Hamano <gitster@pobox.com> writes:

> Of course none of the above becomes unnecessary if we scan the whole
> string for SP before the main loop in quote-c-style-counted, but the
> function was written to process the input in a single pass and such
> a change defeats its design.  If we need to do it in two passes, we
> can have the caller do so anyway, at least for now.  That thinking
> lead to the final organization of the series, with two steps that
> used to be preparatory for passing the flag down thru to the bottom
> layer rebased out as a discardable appendix at the end.

Actually, this made me realize that another variant is possible.
It might be easier to read, or it might not.  Since I cannot tell
without actually writing one, let's see ...

Instead of scanning the output from quote-c-style-counted for SP in
the caller, the caller can do something like this.

/* quote path as relative to the given prefix */
char *quote_path(const char *in, const char *prefix, struct strbuf *out, unsigned flags)
{
	struct strbuf sb = STRBUF_INIT;
	const char *rel = relative_path(in, prefix, &sb);
	int add_dq_ourselves = !!(flags & QUOTE_PATH_QUOTE_SP) && !!strchr(rel, ' ');

	strbuf_reset(out);
        if (add_dq_ourselves)
        	strbuf_addch(out, '"');
	quote_c_style_counted(rel, strlen(rel), out, NULL,
        		      add_dq_ourselves ? CQUOTE_NODQ : 0);
        if (add_dq_ourselves)
        	strbuf_addch(out, '"');
	strbuf_release(&sb);

	return out->buf;
}

That is, we tell quote-c-style-counted not to put dq-pair around its
output whether it needs to do the backslash quoting, if we know we
want the result inside dq-pair anyway (iow, when the caller wants us
to treat SP specially and we do see SP in the input).

I don't know if this is easier to follow or not.  I do think so
right now but that is only because it is still fresh in my brain.