[PATCH v2 0/4] maintenance: use XDG config if it exists

I use the conventional XDG config path for the global configuration. This path is always used except for `git maintenance register` and `unregister`.

§ Changes since v1

• Free `config_file`
  • https://lore.kernel.org/git/ZTZDsIcrB0zwHlFR@tanuki/
• Return `NULL` instead of dying
  • https://lore.kernel.org/git/ZTZDqToqcsDiS5AP@tanuki/
• Tests
  • Test unregister
  • Use subshells
  • Style

§ Patches

• 1–3: Preparatory • 4: The desired change

§ CC

• Patrick Steinhardt: `config` changes; v1 feedback • Derrick Stolee: `maintenance` changes • Eric Sunshine: v1 feedback • Taylor Blau: v1 feedback

Kristoffer Haugsbakk (4):
  config: format newlines
  config: rename global config function
  config: factor out global config file retrieval
  maintenance: use XDG config if it exists

 builtin/config.c       | 26 +++---------------------
 builtin/gc.c           | 27 ++++++++++++-------------
 builtin/var.c          |  2 +-
 config.c               | 26 ++++++++++++++++++++----
 config.h               |  6 +++++-
 t/t7900-maintenance.sh | 45 ++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 89 insertions(+), 43 deletions(-)

Range-diff against v1:
1:  39934cb7e50 = 1:  d5f6c8d62ec config: format newlines
2:  48a5357f97c = 2:  cbc5fde0094 config: rename global config function
3:  147c767443c ! 3:  32e5ec7d866 config: factor out global config file retrieval
    @@ Commit message

         Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>

    +
    + ## Notes (series) ##
    +    v2:
    +    • Don’t die; return `NULL`
    +
      ## builtin/config.c ##
     @@ builtin/config.c: int cmd_config(int argc, const char **argv, const char *prefix)
      	}
    @@ builtin/config.c: int cmd_config(int argc, const char **argv, const char *prefix
     -			 * location; error out even if XDG_CONFIG_HOME
     -			 * is set and points at a sane location.
     -			 */
    --			die(_("$HOME not set"));
    --
     +		given_config_source.file = git_global_config();
    ++		if (!given_config_source.file)
    + 			die(_("$HOME not set"));
    +-
      		given_config_source.scope = CONFIG_SCOPE_GLOBAL;
     -
     -		if (access_or_warn(user_config, R_OK, 0) &&
    @@ config.c: char *git_system_config(void)
     +	char *user_config, *xdg_config;
     +
     +	git_global_config_paths(&user_config, &xdg_config);
    -+	if (!user_config)
    -+		/*
    -+		 * It is unknown if HOME/.gitconfig exists, so
    -+		 * we do not know if we should write to XDG
    -+		 * location; error out even if XDG_CONFIG_HOME
    -+		 * is set and points at a sane location.
    -+		 */
    -+		die(_("$HOME not set"));
    ++	if (!user_config) {
    ++		free(xdg_config);
    ++		return NULL;
    ++	}
     +
     +	if (access_or_warn(user_config, R_OK, 0) && xdg_config &&
     +	    !access_or_warn(xdg_config, R_OK, 0)) {
    @@ config.h: int config_error_nonbool(const char *);
      #endif

      char *git_system_config(void);
    ++/**
    ++ * Returns `NULL` if is uncertain whether or not `HOME/.gitconfig` exists.
    ++ */
     +char *git_global_config(void);
      void git_global_config_paths(char **user, char **xdg);

4: 1e2376a4b99 < -: ----------- maintenance: use XDG config if it exists -: ----------- > 4: 8bd67c5bf01 maintenance: use XDG config if it exists -- 2.43.0