Re: Sparse Checkout Trouble (2.5.0)

[Derrick Stolee <stolee@gmail.com>]

On 1/21/2020 7:42 PM, JunkYardMail1 wrote:
> I have a shallow repository clone and using sparse-checkout of just a
> handful of directories.  When I upgraded from git version 2.24.1 to 2.25.0
> some files not in the sparse-checkout were staged to be deleted.  The
> directory path of these files contain the Windows reserved name of "prn".
> Ex: "japanese/prn/. . ."  Unable to un-stage these files and reset the
> changes.

Are you using Git for Windows? I'm not sure why the "prn" would be important
otherwise.

> !/*/
> /*/directory-*/

I don't see anything complicated with these patterns, although they seem
a bit strange. Why would you not want anything in a directory except one
named "<something>/directory-<anotherthing>/"? Is this actually the exact
pattern set?
 
> Reverting back to the previous version (2.24.1) allowed to un-stage the
> files and reset the changes.

This is definitely pointing to a regression, and the feature did get a
bit of an overhaul. The goal was to not change how existing users
interacted with it, though, so this is a bit alarming.

I did find a behavior change related to these paths in Git for Windows
2.25.0 versus 2.24.1:

  $ git clone https://github.com/derrickstolee/git-sparse-checkout-test
  Cloning into 'git-sparse-checkout-test'...
  remote: Enumerating objects: 6, done.
  remote: Counting objects: 100% (6/6), done.
  remote: Compressing objects: 100% (4/4), done.
  remote: Total 6 (delta 0), reused 6 (delta 0), pack-reused 0
  Receiving objects: 100% (6/6), done.
  error: invalid path 'directory-1/prn/a'
  fatal: unable to checkout working tree
  warning: Clone succeeded, but checkout failed.
  You can inspect what was checked out with 'git status'
  and retry with 'git restore --source=HEAD :/'
  
The checkout here is _expected_ to fail, due to the protected
filenames. What is troublesome is the following sparse-checkout
commands fail, and the read-tree command fails in a way that
2.24.1 does not:
 
  $ git sparse-checkout init
  error: invalid path 'directory-1/prn/a'
  error: invalid path 'directory-1/prn/a'
  
  $ git sparse-checkout set "/*" "\!/*/"
  error: invalid path 'directory-1/prn/a'
  error: invalid path 'directory-1/prn/a'
  
  $ git read-tree -mu HEAD
  error: invalid path 'directory-1/prn/a'

The double error messages are due to the "try with an in-memory
pattern set, then roll back if there is a failure." The patterns
we are trying to create do not include the directory that is failing.

I'll keep looking into this.

Thanks,
-Stolee