[PATCH/resent 0/9] Sparse checkout (first half)

This is the first half of the series, making git ready for sparse
checkout. The only difference from the last (first half) sent
series is safeguard bitmask fix in 1/9

Nguyá»
n Thái Ngọc Duy (9):
  Extend index to save more flags
  Introduce CE_NO_CHECKOUT bit
  ls-files: add options to support sparse checkout
  update-index: refactor mark_valid() in preparation for new options
  update-index: add --checkout/--no-checkout to update CE_NO_CHECKOUT
    bit
  ls-files: Add tests for --sparse and friends
  Prevent diff machinery from examining worktree outside sparse
    checkout
  checkout_entry(): CE_NO_CHECKOUT on checked out entries.
  grep: skip files outside sparse checkout area

 .gitignore                            |    1 +
 Documentation/git-checkout.txt        |   34 +++++++++++++++++
 Documentation/git-grep.txt            |    4 +-
 Documentation/git-ls-files.txt        |   24 +++++++++++-
 Documentation/git-update-index.txt    |   13 ++++++
 Makefile                              |    2 +-
 builtin-grep.c                        |    7 +++-
 builtin-ls-files.c                    |   41 ++++++++++++++++++--
 builtin-update-index.c                |   40 ++++++++++++-------
 cache.h                               |   66 +++++++++++++++++++++++++++++++--
 diff-lib.c                            |    5 +-
 diff.c                                |    4 +-
 entry.c                               |    1 +
 read-cache.c                          |   57 ++++++++++++++++++++++------
 t/t2104-update-index-no-checkout.sh   |   36 ++++++++++++++++++
 t/t3004-ls-files-sparse.sh            |   40 ++++++++++++++++++++
 t/t3004/cached.expected               |    5 ++
 t/t3004/deleted.expected              |    1 +
 t/t3004/everything.expected           |   10 +++++
 t/t3004/modified.expected             |    2 +
 t/t3004/no-checkout.expected          |    2 +
 t/t3004/orphaned-no-checkout.expected |    3 +
 t/t3004/orphaned.expected             |    1 +
 t/t3004/others.expected               |    2 +
 t/t3004/sparse-cached.expected        |    3 +
 t/t3004/sparse-everything.expected    |   11 +++++
 test-index-version.c                  |   14 +++++++
 27 files changed, 385 insertions(+), 44 deletions(-)
 create mode 100755 t/t2104-update-index-no-checkout.sh
 create mode 100755 t/t3004-ls-files-sparse.sh
 create mode 100644 t/t3004/cached.expected
 create mode 100644 t/t3004/deleted.expected
 create mode 100644 t/t3004/everything.expected
 create mode 100644 t/t3004/modified.expected
 create mode 100644 t/t3004/no-checkout.expected
 create mode 100644 t/t3004/orphaned-no-checkout.expected
 create mode 100644 t/t3004/orphaned.expected
 create mode 100644 t/t3004/others.expected
 create mode 100644 t/t3004/sparse-cached.expected
 create mode 100644 t/t3004/sparse-everything.expected
 create mode 100644 test-index-version.c