This patch series includes a fix to the bug reported by Sean Allred [1] and
diagnosed by Eric Sunshine [2].

The root cause is that 'git sparse-checkout init' writes to the worktree
config without checking that core.bare might need to be set. This only
matters when the base repository is bare, since creating the config.worktree
file and enabling extensions.worktreeConfig will cause Git to treat the base
repo's core.bare=false as important for this worktree.

This series fixes this, but also puts in place some helpers to prevent this
from happening in the future. While here, some of the config paths are
modified to take a repository struct.

The critical bits are in Patches 3 and 4 which introduce the helper and then
consume it in builtin/sparse-checkout.c and sparse-index.c.

[1]
https://lore.kernel.org/git/CABceR4bZmtC4rCwgxZ1BBYZP69VOUca1f_moJoP989vTUZWu9Q@mail.gmail.com/
[2]
https://lore.kernel.org/git/CAPig+cQ6U_yFw-X2OWrizB1rbCvc4bNxuSzKFzmoLNnm0GH8Eg@mail.gmail.com/

Thanks, -Stolee

Derrick Stolee (4):
  setup: use a repository when upgrading format
  config: make some helpers repo-aware
  config: add repo_config_set_worktree_gently()
  sparse-checkout: use repo_config_set_worktree_gently()

 builtin/sparse-checkout.c          | 25 +++++--------
 config.c                           | 56 ++++++++++++++++++++++++++++--
 config.h                           | 13 +++++++
 list-objects-filter-options.c      |  2 +-
 repository.h                       |  2 +-
 setup.c                            |  6 ++--
 sparse-index.c                     | 10 ++----
 t/t1091-sparse-checkout-builtin.sh | 14 +++++++-
 8 files changed, 95 insertions(+), 33 deletions(-)

base-commit: 69a9c10c95e28df457e33b3c7400b16caf2e2962

Submitted-As: https://lore.kernel.org/git/pull.1101.git.1640015844.gitgitgadget@gmail.com