Re: Sparse Checkout Trouble (2.5.0)

>
> On 1/21/2020 8:19 PM, Derrick Stolee wrote:
> > On 1/21/2020 7:42 PM, JunkYardMail1 wrote:
> >> 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.
>
> I am still struggling to find out exactly what goes wrong here.
>
> I'm CC'ing Elijah because he also made changes to dir.c, and
> perhaps he has some idea of what's going on.

> Using GIT_TRACE2_PERF=1, I can see that the error appears during
> the traverse_trees() which is after the sparse-checkout patterns
> have applied the skip-worktree bit.
>
> Thanks,
> -Stolee