Re: [RFC/PATCH] Add multiple workdir support to branch/checkout

[Junio C Hamano <gitster@pobox.com>]

Jay Soffian <jaysoffian@gmail.com> writes:

> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index 5e356a6c61..26259a41a7 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -709,12 +710,35 @@ static void orphaned_commit_warning(struct commit *commit)
>  	for_each_ref(clear_commit_marks_from_one_ref, NULL);
>  }
>  
> +static void record_checkout(const char *name, const char *work_tree)
> +{
> +	struct strbuf key = STRBUF_INIT;
> +	strbuf_addf(&key, "branch.%s.checkout", name);
> +	git_config_set(key.buf, work_tree);
> +	strbuf_release(&key);
> +}
> +
> +static void check_if_checked_out(struct checkout_opts *opts, const char *name)
> +{
> +	struct branch *branch = branch_get(name);
> +	if (branch->work_tree && strlen(branch->work_tree) &&
> +	    strcmp(branch->work_tree, get_git_work_tree())) {
> +		if (opts->force)
> +			warning(_("branch '%s' is currently checked out"
> +				  " in '%s'"), name, branch->work_tree);
> +		else
> +			die(_("branch '%s' is currently checked out"
> +			      " in '%s'"), name, branch->work_tree);
> +	}
> +}
> +
>  static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
>  {
>  	int ret = 0;
>  	struct branch_info old;
>  	unsigned char rev[20];
>  	int flag;
> +
>  	memset(&old, 0, sizeof(old));
>  	old.path = xstrdup(resolve_ref("HEAD", rev, 0, &flag));
>  	old.commit = lookup_commit_reference_gently(rev, 1);
> @@ -734,6 +758,9 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
>  		parse_commit(new->commit);
>  	}
>  
> +	if (opts->record_checkouts)
> +		check_if_checked_out(opts, new->name);

The close brace we can see in the context closes "if (!new->name) {", so
this codepath is very well prepared to be called with new->name == NULL.

Is check_if_checked_out() prepared to be called with name == NULL and do
the right thing?

> @@ -743,6 +770,14 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
>  
>  	update_refs_for_switch(opts, &old, new);
>  
> +	if (opts->record_checkouts) {
> +		const char *work_tree = get_git_work_tree();
> +		struct branch *branch = branch_get(old.name);
> +		if (branch->work_tree && !strcmp(branch->work_tree, work_tree))
> +			record_checkout(old.name, "");
> +		record_checkout(new->name, work_tree);
> +	}
> +

Likewise for new->name, but also old.name which is only set when old.path
is set and begins with "refs/heads/" and otherwise NULL.