Re: [PATCH 0/7] Fix some bugs in abspath.c

Junio C Hamano [off-list ref] writes:

mhagger@alum.mit.edu writes:

quoted

Please note that both absolute_path("") and real_path("") used to
return the current directory followed by a slash.  I believe that this
was a bug, and that it is more appropriate for both functions to
reject the empty string.  The evidence is as follows:

* If this were intended behavior, presumably the return value would
  *not* have a trailing slash.

That is weak.  The only thing you can infer from that observation is
that the presense or absense of trailing '/' would not make any
difference to the caller who wanted a path to the cwd (and is more
convenient if the call is made so that a path relative to the cwd is
tucked after it).

I still wonder why you want to reject "" as an input, as it could be
argued that it is a valid way to say the current directory.

What does realpath(3) do?

    ... goes and looks ...

The realpath(3) wants an existing path, and "" naturally gives NOENT,
so we cannot really draw parallel from it.

Ok, let's do this again.

    $ ./test-path-utils absolute_path ""
    /srv/git/git.git/
    $ ./test-path-utils absolute_path "foo"
    /srv/git/git.git/foo

so a caller has to be prepared to see the returned path sometimes
terminated with slash and sometimes without, to form an absolute
path to the file "bar" in the directory it gives to these functions
(i.e. "/srv/git/git.git/bar" vs "/srv/git/git.git/foo/bar").

That is a reasonably good sign that either nobody calls these
functions with "" or existing callers are buggy and would not handle
that case well and need to be fixed anyway.

So I am fine with die() in your patch.

Thanks.

quoted

* I couldn't find any callers that appeared to depend on the old
  behavior.

That is a very good argument (especially if the audit were
thorough).

I would be tempted to say that we should die() on "" for now, cook
the result outside "master" for a few weeks while auditing the
callchains, and see if any of them complains.