Hello, Thank you for all your replies. I am on a case insensitive system (Windows 10) running git version 2.14.1.windows.1. While I can't comment on what the fix would be, it has been enlightening to learn a bit more about what's under the cover of git. TIL :) Pik -----Original Message----- From: Johannes Schindelin [mailto:Johannes.Schindelin@xxxxxx] Sent: Saturday, April 28, 2018 5:44 AM To: Philip Oakley <philipoakley@xxxxxxx> Cc: Jacob Keller <jacob.keller@xxxxxxxxx>; Tang (US), Pik S <Pik.S.Tang@xxxxxxxxxx>; Git List <git@xxxxxxxxxxxxxxx> Subject: Re: Branch deletion question / possible bug? Hi, On Sat, 28 Apr 2018, Philip Oakley wrote: > From: "Jacob Keller" <jacob.keller@xxxxxxxxx> > > On Fri, Apr 27, 2018 at 5:29 PM, Tang (US), Pik S > > <Pik.S.Tang@xxxxxxxxxx> > > wrote: > > > Hi, > > > > > > I discovered that I was able to delete the feature branch I was > > > in, due to some fat fingering on my part and case insensitivity. > > > I never realized this could be done before. A quick google search > > > did not give me a whole lot to work with... > > > > > > Steps to reproduce: > > > 1. Create a feature branch, "editCss" > > > 2. git checkout master > > > 3. git checkout editCSS > > > 4. git checkout editCss > > > 5. git branch -d editCSS > > > > > > > Are you running on a case-insensitive file system? What version of > > git? I thought I recalled seeing commits to help avoid creating > > branches of the same name with separate case when we know we're on a > > file system which is case-insensitive.. > > > > > Normally, it should have been impossible for a user to delete the > > > branch they're on. And the deletion left me in a weird state that > > > took a while to dig out of. > > > > > > I know this was a user error, but I was also wondering if this was a bug. > > > > If we have not yet done this, I think we should. Long term this > > would be fixed by using a separate format to store refs than the > > filesystem, which has a few projects being worked on but none have > > been put into a release. > > Yes, this is an on-going problem on Windows and other case insentive > systems. At the moment the branch name becomes embedded as a file > name, so when Git requests details of a branch from the filesystem, it > can get a case insensitive equivalent. Meanwhile, internally Git is > checking for equality in a case sensitive [Linux] way with obvious > consequences such as this - The most obvious being when there is no > "*" current branch marker in the branch status list. > > It's a bit tricky to fix (internally the name and the path are passed > down different call chains), and depends on how one expects the case > insensitivity to work - the kicker is when someone does an edit of the > name via the file system and expects Git to cope (i.e. devs knowing, > or think they know, too much detail ;-). > > The refs can also get packed, so the "bad spelling" gets baked in. > Ultimately it probably means that GfW and other systems will need a > case sensitivity check when opening paths... FWIW I outlined what I think is the best route to fix this for good: https://github.com/git-for-windows/git/issues/1623#issuecomment-380085257 Essentially, I think we should teach Git the trick to check the spelling before calling lstat() in refs/files-backend.c. To check the spelling, we would need an API to get the on-disk representation of a given path. On Windows, I know this call. On Linux, apparently canonicalize_file_name() might do the job, but that is a GNU libc extension, and won't help us on macOS. Any ideas? Ciao, Dscho
