# [PATCH] prevent checkout from creating branches that start with a dash

4 messages from 2008-07-02 to 2008-07-02. Participants: Bart Trojanowski, Brian Gernhardt, Johannes Sixt.
Thread: https://gitlist.dev/t/14259

## Bart Trojanowski, 2008-07-02 15:01

Subject: [PATCH] prevent checkout from creating branches that start with a dash
Message-ID: <20080702150128.GH26300@jukie.net>
URL: https://gitlist.dev/e/20080702150128.GH26300%40jukie.net

```
It was previously possible to create a -f branch with git-checkout, which
could not be used or deleted.

        $ git checkout -b -f master
        Switched to a new branch "-f"

Signed-off-by: Bart Trojanowski <bart@jukie.net>
---
 branch.c           |   11 +++++++++++
 branch.h           |    5 +++++
 builtin-checkout.c |    4 ++++
 3 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/branch.c b/branch.c
index 56e9492..c25e362 100644
--- a/branch.c
+++ b/branch.c
@@ -170,3 +170,14 @@ void remove_branch_state(void)
 	unlink(git_path("MERGE_MSG"));
 	unlink(git_path("SQUASH_MSG"));
 }
+
+int validate_branch_name(const char *branch_name)
+{
+	if (!*branch_name)
+		return -1;
+
+	if (*branch_name == '-')
+		return -1;
+
+	return 0;
+}
diff --git a/branch.h b/branch.h
index 9f0c2a2..13999ba 100644
--- a/branch.h
+++ b/branch.h
@@ -21,4 +21,9 @@ void create_branch(const char *head, const char *name, const char *start_name,
  */
 void remove_branch_state(void);
 
+/*
+ * Check if the branch name given is well formed.  Returns 0 on success.
+ */
+int validate_branch_name(const char *branch_name);
+
 #endif
diff --git a/builtin-checkout.c b/builtin-checkout.c
index 93ea69b..f425646 100644
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -553,6 +553,10 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	if (opts.force && opts.merge)
 		die("git checkout: -f and -m are incompatible");
 
+	if (opts.new_branch && validate_branch_name(opts.new_branch))
+		die("git checkout: '%s' does not look like a valid branch name",
+				opts.new_branch);
+
 	if (argc) {
 		const char **pathspec = get_pathspec(prefix, argv);
 
-- 
1.5.6.1.109.ga974cd.dirty

```

## Brian Gernhardt, 2008-07-02 15:22

Subject: Re: [PATCH] prevent checkout from creating branches that start with a dash
Message-ID: <3B740C23-95C7-44AD-8A36-9EFA2EEF0E8A@silverinsanity.com>
URL: https://gitlist.dev/e/3B740C23-95C7-44AD-8A36-9EFA2EEF0E8A%40silverinsanity.com
In-Reply-To: <20080702150128.GH26300@jukie.net>

```

On Jul 2, 2008, at 11:01 AM, Bart Trojanowski wrote:

> +	if (opts.new_branch && validate_branch_name(opts.new_branch))
> +		die("git checkout: '%s' does not look like a valid branch name",
> +				opts.new_branch);
> +
> 	if (argc) {
> 		const char **pathspec = get_pathspec(prefix, argv);

Perhaps this should have !opts.force in that if?  That way if someone  
needs something like "-mm" branch, they can have it.

And that way, if people really want to shoot themselves in the foot  
with a -f branch, they can?  "git branch -f -b -f"?

~~ Brian

```

## Johannes Sixt, 2008-07-02 15:38

Subject: Re: [PATCH] prevent checkout from creating branches that start with a dash
Message-ID: <486BA0DD.5030608@viscovery.net>
URL: https://gitlist.dev/e/486BA0DD.5030608%40viscovery.net
In-Reply-To: <20080702150128.GH26300@jukie.net>

```
Bart Trojanowski schrieb:
> It was previously possible to create a -f branch with git-checkout, which
> could not be used or deleted.
> 
>         $ git checkout -b -f master
>         Switched to a new branch "-f"

"-f" *is* a valid branch name and can be used and deleted:

$ git checkout -b -f next
Switched to a new branch "-f"
$ git checkout next
Switched to branch "next"
Your branch is ahead of the tracked remote branch 'origin/next' by 2 commits.
$ git checkout -- -f
Switched to branch "-f"
$ git checkout next
Switched to branch "next"
Your branch is ahead of the tracked remote branch 'origin/next' by 2 commits.
$ git branch -d -- -f
Deleted branch -f.

-- Hannes

```

## Bart Trojanowski, 2008-07-02 16:34

Subject: Re: [PATCH] prevent checkout from creating branches that start with a dash
Message-ID: <20080702163431.GI26300@jukie.net>
URL: https://gitlist.dev/e/20080702163431.GI26300%40jukie.net
In-Reply-To: <486BA0DD.5030608@viscovery.net>

```
* Johannes Sixt <j.sixt@viscovery.net> [080702 12:00]:
> Bart Trojanowski schrieb:
> > It was previously possible to create a -f branch with git-checkout, which
> > could not be used or deleted.
> > 
> >         $ git checkout -b -f master
> >         Switched to a new branch "-f"
> 
> "-f" *is* a valid branch name and can be used and deleted:

Thanks, that I didn't know.

-Bart

-- 
				WebSig: http://www.jukie.net/~bart/sig/

```