[PATCH 00/20] parse-options: handle subcommands

Several Git commands have subcommands to implement mutually exclusive
"operation modes", and they usually parse their subcommand argument
with a bunch of if-else if statements.

Teach parse-options to handle subcommands as well, which will result
in shorter and simpler code with consistent error handling and error
messages on unknown or missing subcommand, and it will also make
possible for our Bash completion script to handle subcommands
programmatically in a follow-up series [1].

Patches 1-8 are a mix of preparatory cleanups, documentation updates, and
test coverage improvements.

Patch 9 is the most important one, which teaches parse-options to handle
subcommands.

The remaining 10-20 convert most builtin commands with subcommands one by
one to use parse-options to handle their subcommand parameters.


This patch series has two conflicts with 'seen' (but none with 'next'):

  - builtin/bisect.c: after the conversion/rename from 'bisect--helper',
    cmd_bisect() doesn't use parse-options anymore.  Take what's on 'seen'
    to resolve the conflict.
    Note that the conflicting topic should have marked cmd_bisect() with
    the NO_PARSEOPT flag in 'git.c's command list.

  - builtin/stash.c: add OPT_SUBCOMMAND entries for the two new
    subcommands 'export' and 'import' to resolve the conflict.


[1] WIP with some one-liner commit messages and missing sign-offs here and
    there:

      https://github.com/szeder/git completion-subcommands


SZEDER Gábor (20):
  git.c: update NO_PARSEOPT markings
  t3301-notes.sh: check that default operation mode doesn't take
    arguments
  t5505-remote.sh: check the behavior without a subcommand
  t0040-parse-options: test parse_options() with various
    'parse_opt_flags'
  api-parse-options.txt: fix description of OPT_CMDMODE
  parse-options: PARSE_OPT_KEEP_UNKNOWN only applies to --options
  parse-options: clarify the limitations of PARSE_OPT_NODASH
  parse-options: drop leading space from '--git-completion-helper'
    output
  parse-options: add support for parsing subcommands
  builtin/bundle.c: let parse-options parse subcommands
  builtin/commit-graph.c: let parse-options parse subcommands
  builtin/gc.c: let parse-options parse 'git maintenance's subcommands
  builtin/hook.c: let parse-option parse subcommands
  builtin/multi-pack-index.c: let parse-options parse subcommands
  builtin/notes.c: let parse-options parse subcommands
  builtin/reflog.c: let parse-options parse subcommands
  builtin/remote.c: let parse-options parse subcommands
  builtin/sparse-checkout.c: let parse-options parse subcommands
  builtin/stash.c: let parse-options parse subcommands
  builtin/worktree.c: let parse-options parse subcommands

 Documentation/technical/api-parse-options.txt |  49 +++-
 builtin/archive.c                             |   2 +-
 builtin/bisect--helper.c                      |   2 +-
 builtin/blame.c                               |   1 +
 builtin/bundle.c                              |  25 +-
 builtin/commit-graph.c                        |  30 +--
 builtin/difftool.c                            |   2 +-
 builtin/env--helper.c                         |   2 +-
 builtin/fast-export.c                         |   2 +-
 builtin/gc.c                                  |  42 +--
 builtin/hook.c                                |  12 +-
 builtin/log.c                                 |   4 +-
 builtin/multi-pack-index.c                    |  51 ++--
 builtin/notes.c                               |  43 ++-
 builtin/reflog.c                              |  43 +--
 builtin/remote.c                              |  70 +++--
 builtin/revert.c                              |   2 +-
 builtin/shortlog.c                            |   1 +
 builtin/sparse-checkout.c                     |  48 ++--
 builtin/stash.c                               |  59 ++--
 builtin/worktree.c                            |  31 +--
 diff.c                                        |   2 +-
 git.c                                         |  14 +-
 parse-options.c                               | 118 +++++++-
 parse-options.h                               |  27 +-
 t/helper/test-parse-options.c                 | 129 +++++++++
 t/helper/test-serve-v2.c                      |   2 +-
 t/helper/test-tool.c                          |   2 +
 t/helper/test-tool.h                          |   2 +
 t/t0040-parse-options.sh                      | 255 ++++++++++++++++++
 t/t3301-notes.sh                              |   5 +
 t/t3903-stash.sh                              |   2 +-
 t/t5318-commit-graph.sh                       |   4 +-
 t/t5505-remote.sh                             |  29 ++
 t/t7900-maintenance.sh                        |  10 +-
 35 files changed, 812 insertions(+), 310 deletions(-)

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2.37.1.633.g6a0fa73e39