Creating branch can fail silently

Description

If I have a branch enhancement/1 and I try to create enhancement/1/test in the desktop GUI, it doesn’t create the branch as expected.

Version

• GitHub Desktop: 1.4.3
• Operating system: Microsoft Windows [Version 6.1.7601]

Steps to Reproduce

1. Create any branch with this format: some/branch/name
2. Attempt to create a branch using the name from step 1 like this: some/branch/name/any/number/of/slashes

Expected Behavior

I would have expected that the branch would be created or that I would be notified that it couldn’t be created.

Actual Behavior

The create branch box closes with no error indication and no branch created.

Additional Information

I did attempt to create a similar structure branch in git and received this error:

git branch "enhancement/1/test"
fatal: cannot lock ref 'refs/heads/enhancement/1/test': 'refs/heads/enhancement/1' exists; cannot create 'refs/heads/enhancement/1/test'

Logs

2018-10-25.desktop.production.log

[j-f1]

That message feels confusing to me since the user might not realize they’re creating files and folders when they make a new branch.

[NickCraver]

We had this on a project as well, we had /channels (a demo/proof-of-concept branch) which turned into a massive project and we wanted /channels/question-list, /channels/auth-relay, etc. I’m not sure it’s uncommon…I think the transform of something minor into something that grows might hit this case fairly often.

I’d suggest a more generic error message, telling the user:

This branch path name conflicts with an existing path: <conflict branch path>. You can either change this branch or remove the previous branch to continue.

…or some such. Just saying: the fact that it’s directories underneath need not be a concern of the user IMO, I agree with others here on that front.