Re: [PATCH 2/2] config: resolve symlinks in conditional include's patterns

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

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

> $GIT_DIR returned by get_git_dir() is normalized, with all symlinks
> resolved (see setup_work_tree function). In order to match paths (or
> patterns) against $GIT_DIR char-by-char, they have to be normalized
> too. There is a note in config.txt about this, that the user need to
> resolve symlinks by themselves if needed.
>
> The problem is, we allow certain path expansion, '~/' and './', for
> convenience and can't ask the user to resolve symlinks in these
> expansions. Make sure the expanded paths have all symlinks resolved.

That sounds sensible but I fail to see why 1/2 is the right approach
to do this, and I must be missing something.  Wouldn't you get the
same result if you run realpath() yourself on expanded, after
receiving the return value of expand_user_path() in it?

Can you add a test to demonstrate the issue (which would need to be
protected with SYMLINKS prereq)?

Thanks.

> PS. The strbuf_realpath(&text, get_git_dir(), 1) is still needed because
> get_git_dir() may return relative path.
>
> Noticed-by: Torsten Bögershausen <tboegi@web.de>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
>  config.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/config.c b/config.c
> index f036c721e6..d5ba848b65 100644
> --- a/config.c
> +++ b/config.c
> @@ -177,7 +177,7 @@ static int prepare_include_condition_pattern(struct strbuf *pat)
>  	char *expanded;
>  	int prefix = 0;
>  
> -	expanded = expand_user_path(pat->buf, 0);
> +	expanded = expand_user_path(pat->buf, 1);
>  	if (expanded) {
>  		strbuf_reset(pat);
>  		strbuf_addstr(pat, expanded);
> @@ -191,7 +191,7 @@ static int prepare_include_condition_pattern(struct strbuf *pat)
>  			return error(_("relative config include "
>  				       "conditionals must come from files"));
>  
> -		strbuf_add_absolute_path(&path, cf->path);
> +		strbuf_realpath(&path, cf->path, 1);
>  		slash = find_last_dir_sep(path.buf);
>  		if (!slash)
>  			die("BUG: how is this possible?");
> @@ -213,7 +213,7 @@ static int include_by_gitdir(const char *cond, size_t cond_len, int icase)
>  	struct strbuf pattern = STRBUF_INIT;
>  	int ret = 0, prefix;
>  
> -	strbuf_add_absolute_path(&text, get_git_dir());
> +	strbuf_realpath(&text, get_git_dir(), 1);
>  	strbuf_add(&pattern, cond, cond_len);
>  	prefix = prepare_include_condition_pattern(&pattern);