[RFC PATCH v3 0/8] Sparse checkout

Continuing the endless RFCs of sparse checkout, this series drops the sparse hook in favor of .git/info/sparse. Changes from the last version

  Prevent diff machinery from examining assume-unchanged entries on worktree

    "if (ce_uptodate(ce) || CE_VALID)" is updated, as well as the corresponding test

  Avoid writing to buffer in add_excludes_from_file_1()

    Splitted out from the old second patch, as suggested by Johannes

  Read .gitignore from index if it is assume-unchanged

    read_index_data() is renamed. Commit message mentions add_excludes_from_file()

  excluded_1(): support exclude "directories" in index

    This one is new because index does not have "directory", more comments in the patch

  dir.c: export excluded_1() and add_excludes_from_file_1()

    New too, exported for use in unpack-trees.c

  unpack-trees.c: generalize verify_* functions

    Splitted out of the old third patch for easier review

  Support sparse checkout in unpack_trees() and read-tree

    Read .git/info/sparse instead of .git/hooks/sparse

    
  --sparse for porcelains
    RFC patch

 Documentation/technical/api-directory-listing.txt |    3 +
 builtin-checkout.c                                |    4 +
 builtin-clean.c                                   |    5 +-
 builtin-ls-files.c                                |    4 +-
 builtin-merge.c                                   |    5 +-
 builtin-read-tree.c                               |    4 +-
 cache.h                                           |    3 +
 diff-lib.c                                        |    6 +-
 dir.c                                             |  101 +++++++++++------
 dir.h                                             |    4 +
 git-pull.sh                                       |    6 +-
 t/t1009-read-tree-sparse.sh                       |   47 ++++++++
 t/t3001-ls-files-others-exclude.sh                |   22 ++++
 t/t4039-diff-assume-unchanged.sh                  |   31 ++++++
 t/t7300-clean.sh                                  |   19 ++++
 unpack-trees.c                                    |  121 ++++++++++++++++++++-
 unpack-trees.h                                    |    3 +
 17 files changed, 340 insertions(+), 48 deletions(-)
 create mode 100755 t/t1009-read-tree-sparse.sh
 create mode 100755 t/t4039-diff-assume-unchanged.sh