git checkout hangs when its current working directory has no files in the target branch of the checkout command

[wilbaker]

• I was not able to find an open or closed issue matching what I'm seeing

Setup

• Which version of Git for Windows are you using? Is it 32-bit or 64-bit?

$ git --version --build-options

git version 2.11.1.windows.1
built from commit: 1c1842bcba45569a84112ec64f72b08eb2d57c68
sizeof-long: 4
machine: x86_64

• Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

Windows 10, 64-bit

$ cmd.exe /c ver

Microsoft Windows [Version 10.0.14393]

• What options did you set as part of the installation? Or did you choose the
  defaults?

# One of the following:
> type "C:\Program Files\Git\etc\install-options.txt"
> type "C:\Program Files (x86)\Git\etc\install-options.txt"
> type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

C:\Repos\gvfsGitTest\Scripts>type "C:\Program Files\Git\etc\install-options.txt"
Path Option: Cmd
SSH Option: OpenSSH
CRLF Option: CRLFCommitAsIs
Bash Terminal Option: MinTTY
Performance Tweaks FSCache: Enabled
Use Credential Manager: Enabled
Enable Symlinks: Disabled
Enable Builtin Difftool: Disabled

• Any other interesting things about your environment that might be related
  to the issue you're seeing?

No

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

CMD

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

C:\Repos>git clone https://github.com/git-for-windows/git
C:\Repos>cd git\xdiff
C:\Repos\git\xdiff>del *
C:\Repos\git\xdiff\*, Are you sure (Y/N)? Y

[NOTE: xdiff is a folder with no subfolders inside of it, only files]

C:\Repos\git\xdiff>git checkout -b b1
C:\Repos\git\xdiff>git commit -a -m "del"
C:\Repos\git\xdiff>git checkout master
C:\Repos\git\xdiff>git checkout b1

• What did you expect to occur after running these commands?

The final "git checkout b1" command (see above) would complete

• What actually happened instead?

The "git checkout b1" command hung

• If the problem was occurring with a specific repository, can you provide the
  URL to that repository to help us with testing?

Not repo specific

[dscho]

@wilbaker thank you for your report!

Funnily enough, this is a duplicate of #1062, even if it does not look like it at all.

The reason why it hangs is that it actually failed to delete the directory xdiff. Which makes sense because this is the current directory, so it cannot be deleted. What Git did was to print an error message

Deletion of directory 'xdiff' failed. Should I try again? (y/n)

and now waits for your input.

Except for one little detail... There is a bug in v2.11.1 where the error output is buffered, i.e. it is not printed immediately but the C runtime waits for "enough" characters to be printed before actually printing anything. This is wrong, of course, as the error output should always be immediate, i.e. unbuffered.

This has been fixed in master: 87ad093

I plan to provide at least a prerelease by the end of the week, or even a v2.11.1(2).