Re: [PATCH] Add option -b/--branch to clone for select a new HEAD

> Sometimes (especially on production systems) we need to use only one
> remote branch for building software. It's really annoying to clone
> origin and then switch branch by hand everytime. So this patch
> provides functionality to clone a remote branch with one command
> without using checkout after clone.
> 
> Signed-off-by: Kirill A. Korinskiy <catap@catap.ru>
> ---
>  Documentation/git-clone.txt |    4 ++++
>  builtin-clone.c             |   23 ++++++++++++++++++++---
>  t/t5706-clone-branch.sh     |   31 +++++++++++++++++++++++++++++++
>  3 files changed, 55 insertions(+), 3 deletions(-)
>  create mode 100755 t/t5706-clone-branch.sh
> 
> diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
> index 2c63a0f..50446d2 100644
> --- a/Documentation/git-clone.txt
> +++ b/Documentation/git-clone.txt
> @@ -127,6 +127,10 @@ objects from the source repository into a pack in the cloned repository.
>  	Instead of using the remote name 'origin' to keep track
>  	of the upstream repository, use <name>.
>  
> +--branch <name>::
> +-b <name>::
> +	Instead of using the remote HEAD as master, use <name> branch.

> @@ -65,6 +66,8 @@ static struct option builtin_clone_options[] = {
>  		   "reference repository"),
>  	OPT_STRING('o', "origin", &option_origin, "branch",
>  		   "use <branch> instead of 'origin' to track upstream"),
> +	OPT_STRING('b', "branch", &option_branch, "branch",
> +		   "use <branch> from 'origin' as HEAD"),

> @@ -518,7 +521,21 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
>  
>  		mapped_refs = write_remote_refs(refs, refspec, reflog_msg.buf);
>  
> -		remote_head = find_ref_by_name(refs, "HEAD");
> +		if (option_branch) {
> +			strbuf_addf(&branch_head, "%s%s", src_ref_prefix, option_branch);
> +
> +			remote_head = find_ref_by_name(refs, branch_head.buf);
> +		}
> +
> +		if (!remote_head) {
> +			if (option_branch)
> +				warning("Remote branch %s not found in upstream %s"
> +					", using HEAD instead",
> +					option_branch, option_origin);
> +
> +			remote_head = find_ref_by_name(refs, "HEAD");
> +		}
> +
>  		head_points_at = guess_remote_head(remote_head, mapped_refs, 0);

>  	}
>  	else {
> diff --git a/t/t5706-clone-branch.sh b/t/t5706-clone-branch.sh
> new file mode 100755
> index 0000000..8d83ac8
> --- /dev/null
> +++ b/t/t5706-clone-branch.sh
> @@ -0,0 +1,31 @@
> +#!/bin/sh
> +
> +test_description='branch clone options'
> +. ./test-lib.sh
> +
> +test_expect_success 'setup' '
> +
> +	mkdir parent &&
> +	(cd parent && git init &&
> +	 echo one >file && git add file &&
> +	 git commit -m one && git checkout -b two &&
> +	 echo two >f && git add f && git commit -m two &&
> +	 git checkout master)
> +
> +'
> +
> +test_expect_success 'clone' '
> +
> +	git clone parent clone &&
> +	(cd clone && git rev-parse --verify refs/remotes/origin/master)
> +
> +'
> +
> +test_expect_success 'clone -b' '
> +
> +	git clone -b two parent clone-b &&
> +	(cd clone-b && test $(git rev-parse --verify HEAD) = $(git rev-parse --verify refs/remotes/origin/two))