Derrick Stolee wrote:

On 2/23/2022 1:25 PM, Victoria Dye via GitGitGadget wrote:

quoted

From: Victoria Dye <redacted>

Aside: It looks like you have the same "mailto:" email addresses in the
CC similar to a mistake I made. The root cause of my issue was that I
copy-pasted from the rendered description of another PR instead of
copying the plaintext available by clicking the "Edit" button. Perhaps
this is worth extending GGG to prevent this issue in the future.

quoted

Prevent the repository root from being collapsed into a sparse directory by
treating an empty path as "inside the sparse-checkout". When collapsing a
sparse index (e.g. in 'git sparse-checkout reapply'), the root directory
typically could not become a sparse directory due to the presence of in-cone
root-level files and directories. However, if no such in-cone files or
directories were present, there was no explicit check signaling that the
"repository root path" (an empty string, in the case of
'convert_to_sparse(...)') was in-cone, and a sparse directory index entry
would be created from the repository root directory.

The documentation in Documentation/git-sparse-checkout.txt explicitly states
that the files in the root directory are expected to be in-cone for a
cone-mode sparse-checkout. Collapsing the root into a sparse directory entry
violates that assumption, as sparse directory entries are expected to be
outside the sparse cone and have SKIP_WORKTREE enabled. This invalid state
in turn causes issues with commands that interact with the index, e.g.
'git status'.

Treating an empty (root) path as in-cone prevents the creation of a root
sparse directory in 'convert_to_sparse(...)'. Because the repository root is
otherwise never compared with sparse patterns (in both cone-mode and
non-cone sparse-checkouts), the new check does not cause additional changes
to how sparse patterns are applied.

Good catch! I agree with everything said here.

quoted

+	if (!strlen(path) ||

Instead of a full strlen(), could we just check "if (!*path ||" to
look for the nul byte?

Thanks,
-Stolee

I'll reroll with corrected CC's & make the `strlen` -> `*path` change.
Thanks!