This adds the reftable library, and hooks it up as a ref backend.

Includes testing support, to test: make -C t/ GIT_TEST_REFTABLE=1

Summary 19055 tests pass 2765 tests fail

Some issues:

 * many tests inspect .git/{logs,heads}/ directly.
 * worktrees broken.
 * Rebase/cherry-pick still largely broken

v16

 * handle pseudo refs.
 * various bugfixes and fixes for mem leaks.

Han-Wen Nienhuys (11):
  refs.h: clarify reflog iteration order
  t: use update-ref and show-ref to reading/writing refs
  refs: document how ref_iterator_advance_fn should handle symrefs
  reftable: clarify how empty tables should be written
  reftable: define version 2 of the spec to accomodate SHA256
  Write pseudorefs through ref backends.
  Iterate over the "refs/" namespace in for_each_[raw]ref
  Add .gitattributes for the reftable/ directory
  Add reftable library
  Reftable support for git-core
  Add some reftable testing infrastructure

Johannes Schindelin (1):
  vcxproj: adjust for the reftable changes

Jonathan Nieder (1):
  reftable: file format documentation

 Documentation/Makefile                        |    1 +
 Documentation/technical/reftable.txt          | 1083 ++++++++++++++
 .../technical/repository-version.txt          |    7 +
 Makefile                                      |   27 +-
 builtin/clone.c                               |    3 +-
 builtin/init-db.c                             |   56 +-
 cache.h                                       |    6 +-
 config.mak.uname                              |    2 +-
 contrib/buildsystems/Generators/Vcxproj.pm    |   11 +-
 refs.c                                        |  148 +-
 refs.h                                        |   28 +-
 refs/files-backend.c                          |  164 ++-
 refs/packed-backend.c                         |   40 +-
 refs/refs-internal.h                          |   18 +
 refs/reftable-backend.c                       | 1218 ++++++++++++++++
 reftable/.gitattributes                       |    1 +
 reftable/LICENSE                              |   31 +
 reftable/README.md                            |   11 +
 reftable/VERSION                              |   14 +
 reftable/basics.c                             |  215 +++
 reftable/basics.h                             |   53 +
 reftable/block.c                              |  434 ++++++
 reftable/block.h                              |  129 ++
 reftable/constants.h                          |   21 +
 reftable/file.c                               |   99 ++
 reftable/iter.c                               |  240 ++++
 reftable/iter.h                               |   63 +
 reftable/merged.c                             |  325 +++++
 reftable/merged.h                             |   38 +
 reftable/pq.c                                 |  114 ++
 reftable/pq.h                                 |   34 +
 reftable/reader.c                             |  753 ++++++++++
 reftable/reader.h                             |   65 +
 reftable/record.c                             | 1141 +++++++++++++++
 reftable/record.h                             |  121 ++
 reftable/refname.c                            |  215 +++
 reftable/refname.h                            |   38 +
 reftable/reftable.c                           |   91 ++
 reftable/reftable.h                           |  564 ++++++++
 reftable/slice.c                              |  225 +++
 reftable/slice.h                              |   76 +
 reftable/stack.c                              | 1245 +++++++++++++++++
 reftable/stack.h                              |   48 +
 reftable/system.h                             |   54 +
 reftable/tree.c                               |   67 +
 reftable/tree.h                               |   34 +
 reftable/update.sh                            |   24 +
 reftable/writer.c                             |  665 +++++++++
 reftable/writer.h                             |   60 +
 reftable/zlib-compat.c                        |   92 ++
 repository.c                                  |    2 +
 repository.h                                  |    3 +
 setup.c                                       |   12 +-
 t/t0002-gitfile.sh                            |    2 +-
 t/t0031-reftable.sh                           |  120 ++
 t/t1400-update-ref.sh                         |   32 +-
 t/t1409-avoid-packing-refs.sh                 |    6 +
 t/t1506-rev-parse-diagnosis.sh                |    2 +-
 t/t3210-pack-refs.sh                          |    6 +
 t/t6050-replace.sh                            |    2 +-
 t/t9020-remote-svn.sh                         |    4 +-
 t/test-lib.sh                                 |    5 +
 62 files changed, 10201 insertions(+), 207 deletions(-)
 create mode 100644 Documentation/technical/reftable.txt
 create mode 100644 refs/reftable-backend.c
 create mode 100644 reftable/.gitattributes
 create mode 100644 reftable/LICENSE
 create mode 100644 reftable/README.md
 create mode 100644 reftable/VERSION
 create mode 100644 reftable/basics.c
 create mode 100644 reftable/basics.h
 create mode 100644 reftable/block.c
 create mode 100644 reftable/block.h
 create mode 100644 reftable/constants.h
 create mode 100644 reftable/file.c
 create mode 100644 reftable/iter.c
 create mode 100644 reftable/iter.h
 create mode 100644 reftable/merged.c
 create mode 100644 reftable/merged.h
 create mode 100644 reftable/pq.c
 create mode 100644 reftable/pq.h
 create mode 100644 reftable/reader.c
 create mode 100644 reftable/reader.h
 create mode 100644 reftable/record.c
 create mode 100644 reftable/record.h
 create mode 100644 reftable/refname.c
 create mode 100644 reftable/refname.h
 create mode 100644 reftable/reftable.c
 create mode 100644 reftable/reftable.h
 create mode 100644 reftable/slice.c
 create mode 100644 reftable/slice.h
 create mode 100644 reftable/stack.c
 create mode 100644 reftable/stack.h
 create mode 100644 reftable/system.h
 create mode 100644 reftable/tree.c
 create mode 100644 reftable/tree.h
 create mode 100755 reftable/update.sh
 create mode 100644 reftable/writer.c
 create mode 100644 reftable/writer.h
 create mode 100644 reftable/zlib-compat.c
 create mode 100755 t/t0031-reftable.sh

base-commit: b994622632154fc3b17fb40a38819ad954a5fb88

Submitted-As: https://lore.kernel.org/git/pull.539.v13.git.1589226388.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.539.git.1579808479.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.539.v2.git.1580134944.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.539.v3.git.1580848060.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.539.v4.git.1581029756.gitgitgadget@gmail.com
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In-Reply-To: https://lore.kernel.org/git/pull.539.v8.git.1585740538.gitgitgadget@gmail.com
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