Git Fetch –prune and Branch Name Case

I posted up the following to the git community mailing list the other day

When using git fetch --prune, git will remove any branches from
remotes/origin/ that have inconsistent case in folder names.

This issue has been verified in versions 1.7.10.2, 1.7.11.1 and 1.8.3.2.

I've described the reproduction steps here as I carried them out, and
listed the plaforms I used to replicate it.  The issue will most
likely occur on a different combination of platforms also.

- On Mac, create a new repository and push a master branch to a central server
- On Mac, create a branch called feature/lower_case_branch and push
this to the central server (note that 'feature' is all lower case)
- On Windows, clone the repository but stay on master, do not checkout
the feature/lower_case_branch branch
- On Windows, branch from master a branch called
Feature/upper_case_branch (note the uppercase F) and push to the
server
- On Mac, run git fetch and see that
remote/origin/Feature/upper_case_branch is updated

Couple of things to note here
1) In the git fetch output it lists the branch with an upper case 'F'
  * [new branch]      Feature/upper_case_branch ->
origin/Feature/upper_case_branch
2) When I run git branch --all it is actually listed with a lower case 'f'
  remotes/origin/feature/upper_case_branch

Now the problem happens when I run git fetch --prune, I get the following output
  * [new branch]      Feature/upper_case_branch ->
origin/Feature/upper_case_branch
  x [deleted]         (none)     -> origin/feature/upper_case_branch

Note the new branch uses 'F' and the deleted branch uses 'f'.

The results of this bug seem to be
* Everytime I call git fetch it thinks Feature/upper_case_branch is a
new branch (if I call 'git branch' multiple times I always get the
[new branch] output)
* Whenever I run with --prune, git will *always* remove the branch
with a different folder name (from a case sensitive perspective) than
the one originally created on the current machine.

I’ve yet to receive a response as to whether this is an actual bug (certainly looks like it) or expected behaviour, but it caused quite a bit of running around trying to find a solution to it (I originally thought it was a SourceTree bug).  Since our branches are extremely transient, we use –prune a lot so not being able to use it would have caused quite a few issues.

Luckily it can be worked around by calling ‘git fetch –prune’ followed directly with ‘git fetch’ and depending on what tool you’re using, adding this as a custom step is usually pretty easy.

Here’s the link to the list thread if you want to follow it.