Subject: Re: Possible submodule or submodule documentation issue

From: Bill Zaumen <[email-masked]>
Date: Wed, 28 Dec 2011 18:50:30 -0800

On Wed, 2011-12-28 at 20:47 +0100, Jens Lehmann wrote:
> Am 27.12.2011 20:24, schrieb Bill Zaumen:
> > For the 'add' command, the man page for get-submodule states
> > 
> > "<repository> is the URL of the new submodule’s origin repository. This
> > may be either an absolute URL, or (if it begins with ./ or ../), the
> > location relative to the superproject’s origin repository."
> >
...

> I assume you did forget to add a "cd library-pkg" here.

Yes, sorry for miscopying.

> 
> Hmm, the documentation says "the location relative to the
> superproject’s origin repository", not the directory containing
> it. This means you have to use ".." first to get out of the
> repository itself, no?

The problem is  that the documentation also says that "<repository>
is the URL of the new submodule's origin repository" and the wording
would not make sense if the superproject's origin repository was not
also named by a URL.  The rules for resolving relative URIs (a URL is
a specific type of URI) are given in
http://tools.ietf.org/html/rfc3986#section-5.4
which has some examples:  if you resolve ./g against http://a/b/c/d;p?q
you get http://a/b/c/g (the rules are purely syntactic and the syntax
does not indicate that ".../foo.git" is a directory, and even the
slashes do not definitively indicate directories in the sense of a
file-system directory although they often do).  Also, I've enclosed a
Java program illustrating the correct behavior (a method in the Java
class library can resolve URIs so this is an independent test).

import java.net.*;
public class Test {
    public static void main(String argv[]) {
	try {
	    URI base = new URI("file:///home/USER/Projects/test/repo.git");
	    URI relative = new URI("./submodule.git");
	    URI absolute = base.resolve(relative);
	    System.out.println(relative.toString() + " -> "
			       +absolute.toString());
	    relative = new URI("../submodule.git");
	    absolute = base.resolve(relative);
	    System.out.println(relative.toString() + " -> "
			       +absolute.toString());
	} catch (Exception e) {
	    e.printStackTrace();
	    System.exit(1);
	}
	System.exit(0);
    }
}