Re: [PATCH v3] Documentation/remote-helpers: Add invocation section
Ramkumar Ramachandra wrote:
Show 7 quoted lines
> +INVOCATION
> +----------
> +
> +Remote helper programs are invoked with one or (optionally) two
> +command line arguments. The first argument specifies a remote
> +repository as it would be in git; typically, it is either the name of
> +a configured remote or just a URL.
> The second argument, if present, is
> +a URL, and serves to resolve ambiguities that may arise when only the
> +first argument is specified (i.e. when a remote has more than one
> +configured URL).
This seems to suggest that the remote helper should pay attention primarily to the first argument and then use the second argument to figure out some detail. But AFAICT that is not true.
As I understand it, there are two cases. I will call them the “Subversion-like” (URL-based) and the “Perforce-like” (no URL) cases. See [1] for an example of where I am getting this from, or see [2] for more explanation of what I mean.
A hypothetical ‘git remote-svn’ would not need to examine its first argument at all, unless it wants to use it to name a store of additional per-remote data. From its perspective, the second argument is not to disambiguate. Instead, the second argument is all that matters.
A hypothetical ‘git remote-p4’ might not understand URLs at all. If so, it should error out if the first argument does not correspond to a [remote "foo"] stanza or a second argument is supplied.
Regards, Jonathan
[1] http://thread.gmane.org/gmane.comp.version-control.git/125374/focus=125410 [2] Examples:
In the Subversion-like case, the remote vcs uses a URL to identify the repository. So the configuration might look like
[remote "upstream"]
vcs = svn
url = http://svn.example.com/some/project
svn-fetch = branches/*:refs/remotes/upstream/*:
svn-fetch = trunk:refs/remotes/upstream/trunk
svn-fetch = tags/*:refs/tags/*
or
[remote "upstream"]
url = svn://svn.example.com/some/project
svn-fetch = trunk:refs/remotes/upstream/master
There may be some cases in which this supposed URL should not actually be a URL, as in:
[remote "upstream"]
vcs = svn
url = /path/to/local/repo
svn-fetch = :refs/remotes/upstream/master
and for this reason, the rule is that the URL can be an arbitrary string.
In the Perforce-like case, there is additional configuration required to describe a repository _anyway_, so there is no need for a URL. The configuration looks like this:
[remote "upstream"]
vcs = p4
[p4 "origin"]
find-server-command = ssh bunch of complicated options
random-p4-option = ...
random-other-p4-option = ...
(or so I hear). This case is quite weird in my opinion, but anyway, there is no URL.
Ramkumar Ramachandra