[PATCH v6 0/3] maintenance: add support for systemd timers on Linux

Hello,

Please find hereafter my fixed patchset to add support for systemd
timers on Linux for the `git maintenance start` command.

There are very few changes compared to the previous version.
The main change is the fix for the use-after-free bug that Jeff
pointed out.
Except from that, I’ve done some minor style fixes based on the `git
clang-format --diff …` recommendations.

The patches are:

* cache.h: Introduce a generic "xdg_config_home_for(…)" function

  This patch introduces a function to compute configuration files
  paths inside $XDG_CONFIG_HOME.

  This patch is unchanged compared to its previous version.

* maintenance: `git maintenance run` learned `--scheduler=<scheduler>`

  This patch adds a new parameter to the `git maintenance run` to let
  the user choose a scheduler.

  The only changes in this patch compared to its previous version are
  some code alignment changes that were suggested by `git clang-format
  --diff …`

* maintenance: add support for systemd timers on Linux

  This patch implements the support of systemd timers on top of
  crontab scheduler on Linux systems.

  The only change in this patch compared to its previous version is
  the fix of the use-after-free bug that Jeff pointed out.
  I’ve moved the `free(filename)` after the last usage of `filename`.
  I left the `free(filename)` below the `error` label as the
  `filename` will always be allocated at each `goto error`.

Best wishes,
Lénaïc.

Lénaïc Huard (3):
  cache.h: Introduce a generic "xdg_config_home_for(…)" function
  maintenance: `git maintenance run` learned `--scheduler=<scheduler>`
  maintenance: add support for systemd timers on Linux

 Documentation/git-maintenance.txt |  60 ++++
 builtin/gc.c                      | 562 ++++++++++++++++++++++++++----
 cache.h                           |   7 +
 path.c                            |  13 +-
 t/t7900-maintenance.sh            | 110 +++++-
 5 files changed, 674 insertions(+), 78 deletions(-)

-- 
2.32.0