This series is now based on v2.35.0 since that contains all of the necessary
topics.

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 or core.worktree are set in the
common config file. This series fixes this, but also puts in place some
helpers to prevent this from happening in the future.

ATTENTION: I have significantly redesigned the series since previous
versions, so most of this cover letter is new.

 * Patch 1 updates documentation around extensions.worktreeConfig in a few
   places to improve discoverability. Several cross links are added to make
   it easy to find the related areas. (The documentation for the changes to
   'git sparse-checkout' are delayed to patch 4.)

 * Patch 2 introduces the init_worktree_config() helper which follows the
   documented instructions to enable extensions.worktreeConfig as well as
   move the core.bare and core.worktree config values. This update does not
   modify core.repositoryFormatVersion, since this is not needed
   specifically for extensions.worktreeConfig.

 * Patch 3 adds a new repo_config_set_worktree_gently() helper method so we
   can internally adjust a config value within a worktree, at least if
   extensions.worktreeConfig is enabled. (It will write to the common config
   file if the extension is not enabled.)

 * Patch 4 modifies the sparse-checkout builtin to use
   init_worktree_config() and repo_config_set_worktree_gently() in ways that
   fix the reported bug. The behavior change here is that it will no longer
   upgrade the repository format version, since that is not needed for
   extensions.worktreeConfig.

 * Patch 5 updates 'git worktree add' to copy the worktree config from the
   current worktree to the new one (while unsetting core.bare=true and
   core.worktree=*) along with copying the sparse-checkout patterns file.

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

Updates in v5
=============

 * Cleaned up documentation as per Elijah's suggestions.
 * Removed unnecessary conflicting change in git-sparse-checkout.txt
 * Fixed an ambiguous comment about moving config values.

Updates in v4
=============

 * Rebased to v2.35.0
 * Fixed memory leak (was leaking repo_git_path() result)
 * Added additional documentation updates so curious users can discover the
   intricacies of extensions.worktreeConfig from multiple entry points.
 * Significantly reduced the amount of changes to config.c.
 * 'git sparse-checkout' no longer upgrades the repository format.
 * Dropped the update to upgrade_repository_format(), since it is not
   needed.
 * Dropped the 'git worktree init-worktree-config' subcommand in favor of a
   helper method called by 'git sparse-checkout'
 * Many others because of the significant changes required by the above
   items.

Thanks, -Stolee

Derrick Stolee (5):
  Documentation: add extensions.worktreeConfig details
  worktree: create init_worktree_config()
  config: add repo_config_set_worktree_gently()
  sparse-checkout: set worktree-config correctly
  worktree: copy sparse-checkout patterns and config on add

 Documentation/config/extensions.txt   | 31 ++++++++++++
 Documentation/git-config.txt          |  8 ++-
 Documentation/git-sparse-checkout.txt | 16 ++++--
 Documentation/git-worktree.txt        | 11 +++--
 builtin/sparse-checkout.c             | 28 +++++------
 builtin/worktree.c                    | 60 +++++++++++++++++++++++
 config.c                              | 35 ++++++++++++--
 config.h                              |  8 +++
 sparse-index.c                        | 10 ++--
 t/t1091-sparse-checkout-builtin.sh    | 35 ++++++++++----
 t/t2400-worktree-add.sh               | 46 +++++++++++++++++-
 worktree.c                            | 70 +++++++++++++++++++++++++++
 worktree.h                            | 21 ++++++++
 13 files changed, 333 insertions(+), 46 deletions(-)

base-commit: 89bece5c8c96f0b962cfc89e63f82d603fd60bed

Submitted-As: https://lore.kernel.org/git/pull.1101.v5.git.1643641259.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1101.git.1640015844.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1101.v2.git.1640114048.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1101.v3.git.1640727143.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1101.v4.git.1643136134.gitgitgadget@gmail.com