[PATCH 00/10] run-command API: add run_command_{l,sv}_opt()

This series starts out by addressing the issue Jeff King noted in https://lore.kernel.org/git/Y0TXTl0gSBOFQa9B@coredump.intra.peff.net/; I.e. that by moving away from a "struct strvec" for run_command() variants we lose out on the "warn_unused_result" checking we'd get with the strvec_pushl() (ensuring the last element is NULL).

The 3/10 here adds a run_command_l_opt() function, which provides an easy & safe one-shot API using warn_unused_result.

The 10/10 here then adds a run_command_sv_opt(), which is a run_command_v_opt() taking a "struct strvec" that the API clears for the user after it's called. This makes a lot of one-shot "run this and free the strvec" users less verbose.

Then, having converted to these helpers we had 1-2 users of other run_command_*() variants, which could be moved to using run_command() directly, and thus getting rid of supporting so much shorthand API variation.

At the end of this series the in-tree use of the 3x helpers is (by number of *.c file occurances):

     19 run_command_l_opt
     15 run_command_v_opt
     12 run_command_sv_opt

More can be converted to run_command_{l,sv}_opt(), but I left out e.g. bisect--helper.c to avoid conflicts with anything in-flight.

Ævar Arnfjörð Bjarmason (10):
  run-command.c: refactor run_command_*_tr2() to internal helpers
  merge: remove always-the-same "verbose" arguments
  run-command API: add and use a run_command_l_opt()
  am: use run_command_l_opt() for show_patch()
  run-command API docs: clarify & fleshen out run_command_v_opt*() docs
  run-command API: remove RUN_COMMAND_STDOUT_TO_STDERR flag
  run-command API & diff.c: remove run_command_v_opt_cd_env()
  run-command API & users: remove run_command_v_opt_tr2()
  gc: use strvec_pushf(), avoid redundant strbuf_detach()
  run-command API: add and use a run_command_sv_opt()

 add-interactive.c        |  3 +-
 bisect.c                 | 19 +++++------
 builtin/add.c            |  6 ++--
 builtin/am.c             | 14 +++-----
 builtin/clone.c          | 19 ++++-------
 builtin/difftool.c       | 14 ++++----
 builtin/gc.c             | 49 +++++++++-----------------
 builtin/merge.c          | 46 ++++++-------------------
 builtin/pull.c           | 15 ++------
 builtin/remote.c         | 15 +++-----
 compat/mingw.c           |  8 ++---
 diff.c                   | 26 +++++++-------
 fsmonitor-ipc.c          | 10 ++++--
 git.c                    | 15 ++++----
 ll-merge.c               |  4 +--
 merge.c                  |  3 +-
 run-command.c            | 43 ++++++++++++-----------
 run-command.h            | 74 +++++++++++++++++++++++++++-------------
 scalar.c                 |  6 +---
 sequencer.c              | 15 ++------
 t/helper/test-fake-ssh.c |  4 +--
 tmp-objdir.h             |  6 ++--
 22 files changed, 177 insertions(+), 237 deletions(-)