Subject: Re: [PATCH] path_treatment: also ignore $GIT_DIR if it's not .git

From: Dennis Kaarsemaker <[email-masked]>
Date: Mon, 02 Dec 2013 09:01:14 +0100

On ma, 2013-12-02 at 07:38 +0700, Duy Nguyen wrote:
> On Mon, Dec 2, 2013 at 6:38 AM, Dennis Kaarsemaker
> <[email-masked]> wrote:
> > On ma, 2013-12-02 at 00:08 +0100, Thomas Rast wrote:
> >> Duy Nguyen <[email-masked]> writes:
> >>
> >> > On Mon, Dec 2, 2013 at 2:04 AM, Dennis Kaarsemaker
> >> > <[email-masked]> wrote:
> >> >> We always ignore anything named .git, but we should also ignore the git
> >> >> directory if the user overrides it by setting $GIT_DIR
> >> [...]
> >> >> +       if (simplify_away(path->buf, path->len, simplify) || is_git_directory(path->buf))
> >> >>                 return path_none;
> >> >
> >> > this adds 2 access, 1 lstat, 1 open, 1 read, 1 close to _every_ path
> >> > we check. Is it worth the cost?
> >>
> >> Moreover it is a much more inclusive check than what the commit message
> >> claims: it will ignore anything that looks like a .git directory,
> >> regardless of the name.  In particular GIT_DIR doesn't have anything to
> >> do with it.
> >
> > Ah, yes thanks, that's rather incorrect indeed. How about the following
> > instead? Passes all tests, including the new one.
> >
> > --- a/dir.c
> > +++ b/dir.c
> > @@ -1198,7 +1198,7 @@ static enum path_treatment treat_path(struct dir_struct *dir,
> >                 return path_none;
> >         strbuf_setlen(path, baselen);
> >         strbuf_addstr(path, de->d_name);
> > -       if (simplify_away(path->buf, path->len, simplify))
> > +       if (simplify_away(path->buf, path->len, simplify) || !strncmp(get_git_dir(), path->buf, path->len))
> >                 return path_none;
> 
> get_git_dir() may return a relative or absolute path, depending on
> GIT_DIR/GIT_WORK_TREE. path->buf is always relative. You'll pass one
> case with this (relative vs relative) and fail another. It might be
> simpler to just add get_git_dir(), after converting to relative path
> and check if it's in worktree, to the exclude list and let the current
> exclude mechanism handle it.

This type of invocation really only works from the root of the workdir
anyway and both a relative and absolute path work just fine:

dennis@lightning:~/code/git$ GIT_DIR=$(pwd)/.foo ./git status
On branch master
nothing to commit, working directory clean
dennis@lightning:~/code/git$ GIT_DIR=./.foo ./git status
On branch master
nothing to commit, working directory clean

Well, unless you set GIT_WORK_TREE as well, but then it still works:

dennis@lightning:~/code/git/t$ GIT_DIR=$(pwd)/../.foo GIT_WORK_TREE=.. ../git status
On branch master
nothing to commit, working directory clean
dennis@lightning:~/code/git/t$ GIT_DIR=../.foo GIT_WORK_TREE=.. ../git status
On branch master
nothing to commit, working directory clean

So I'm wondering when you think this will fail. Because then I can add a
test for that case too.

-- 
Dennis Kaarsemaker
www.kaarsemaker.net