Re: [PATCH 4/8] wildmatch: support "no FNM_PATHNAME" mode

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

Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:

> diff --git a/wildmatch.c b/wildmatch.c
> index a79f97e..4fe1d65 100644
> --- a/wildmatch.c
> +++ b/wildmatch.c
> @@ -77,14 +77,17 @@ static int dowild(const uchar *p, const uchar *text, unsigned int flags)
>  			continue;
>  		case '?':
>  			/* Match anything but '/'. */
> -			if (t_ch == '/')
> +			if ((flags & WM_PATHNAME) && t_ch == '/')
>  				return WM_NOMATCH;
>  			continue;
>  		case '*':
>  			if (*++p == '*') {
>  				const uchar *prev_p = p - 2;
>  				while (*++p == '*') {}
> -				if ((prev_p == text || *prev_p == '/') ||
> +				if (!(flags & WM_PATHNAME))
> +					/* without WM_PATHNAME, '*' == '**' */
> +					special = 1;
> +				else if ((prev_p == text || *prev_p == '/') ||

Not a new issue in this patch, but here, "prev_p" points into the
pattern string, two bytes before p, which is the byte before the
"**" that we are looking at (which might be before the beginning of
the pattern).  "text" is the string we are trying to match that
pattern against.  How can these two pointers be compared to yield a
meaningful value?

>  				    (*p == '\0' || *p == '/' ||
>  				     (p[0] == '\\' && p[1] == '/'))) {

OK.  "**/", "**" (end of pattern), and "**\/" are handled here.  

Do we have to worry about "**[/]" the same way, or a class never
matches the directory separator, even if it is a singleton class
that consists of '/' (which is fine by me)?  If so, is "\/" more or
less like "[/]"?