[PATCH v4 0/9] Make submodules work if .gitmodules is not checked out

Hi,

this series teaches git to try and read the .gitmodules file from the index (:.gitmodules) and the current branch (HEAD:.gitmodules) when it is not readily available in the working tree.

This can be used, together with sparse checkouts, to enable submodule usage with programs like vcsh[1] which manage multiple repositories with their working trees sharing the same path.

[1] https://github.com/RichiH/vcsh

In v4 patches 1, 2, 5, 6, and 7 are basically the same as in the previous series; the review can concentrate on patches 3, 4, 8, and 9.

v3 of the series is here: https://public-inbox.org/git/20180814110525.17801-1-ao2@ao2.it/

v2 of the series is here: https://public-inbox.org/git/20180802134634.10300-1-ao2@ao2.it/

v1 of the series, with some background info, is here: https://public-inbox.org/git/20180514105823.8378-1-ao2@ao2.it/

Changes since v3:

  * Improve robustness of current tests in t7411-submodule-config.sh:
      - merge two tests that check for effects of the same commit.
      - reset to a well defined point in history when exiting the tests.

  * Fix style issues in new tests added to t7411-submodule-config.sh:
      - use test_when_finished in new tests.
      - name the output file 'expect' instead of 'expected'.

  * Add a new "submodule--helper config --check-writeable" command.

  * Use "s--h config --check-wrteable" in git-submodule.sh to share the
    code with the C implementation instead of duplicating the safety
    check in shell script.

  * Add the ability to read .gitmodules from the index and then
    fall-back to the current branch if the file is not in the index.
    Add also more tests to validate all the possible scenarios.

  * Fix style issues in t7416-submodule-sparse-gitmodules.sh:
      - name the output file 'expect' instead of 'expected'.
      - remove white space after the redirection operator.
      - indent the HEREDOC block.
      - use "git -C super" instead of a subshell when there is only one
        command in the test.

  * Remove a stale file named 'new' which erroneusly slipped in
    a commit.

  * Update some comments and commit messages.

Thanks,
   Antonio

Antonio Ospite (9):
  submodule: add a print_config_from_gitmodules() helper
  submodule: factor out a config_set_in_gitmodules_file_gently function
  t7411: merge tests 5 and 6
  t7411: be nicer to future tests and really clean things up
  submodule--helper: add a new 'config' subcommand
  submodule: use the 'submodule--helper config' command
  t7506: clean up .gitmodules properly before setting up new scenario
  submodule: add a helper to check if it is safe to write to .gitmodules
  submodule: support reading .gitmodules when it's not in the working
    tree

 builtin/submodule--helper.c            |  40 +++++++++
 cache.h                                |   2 +
 git-submodule.sh                       |  13 ++-
 submodule-config.c                     |  55 ++++++++++++-
 submodule-config.h                     |   3 +
 submodule.c                            |  28 +++++--
 submodule.h                            |   1 +
 t/t7411-submodule-config.sh            | 107 +++++++++++++++++++++----
 t/t7416-submodule-sparse-gitmodules.sh |  78 ++++++++++++++++++
 t/t7506-status-submodule.sh            |   3 +-
 10 files changed, 301 insertions(+), 29 deletions(-)
 create mode 100755 t/t7416-submodule-sparse-gitmodules.sh