Re: [PATCH v7 0/3] branch: inherit tracking configs

Josh Steadmon [off-list ref] writes:

Changes since V6:
* Strip the refs/heads/ prefix in the verbose output when we have only a
  single upstream branch.
* Improve the fatal error message to note that rebasing is only
  incompatible with multiple upstream refs.
* Also note that `branch.<name>.remote` should be set in the manual
  recovery advice.
* Simplify the logic in setup_tracking() when no tracking sources match.
* Make the difference in test cases in t2027 more obvious.

Changes since V5:
* Greatly simplified BRANCH_CONFIG_VERBOSE output to not require nearly
  so many conditionals.
* Note that rebasing is not compatible with inheriting multiple upstream
  branches.
* Moved the change to case-sensitivity for branch.autosetupmerge to its
  own commit.
* Improve advice on failed tracking setup when multiple branches are
  involved.
* Make better use of string_list API.
* Make better use of config API.
* More straight-forward use of the `struct tracking` API.
* Numerous style fixes.

Changes since V4:
* Add new patch (1/2) to refactor branch.c:install_branch_config() to
  accept multiple upstream refs
* When multiple upstream branches are set in the parent branch, inherit
  them all, instead of just the first
* Break out error string arguments for easier translation
* Don't ignore case for values of branch.autosetupmerge
* Move reference to git-pull out of usage string for --track into
  git-branch.txt
* Use test_config instead of `git config` in t2027
* Style fixes: add single-quotes around warning string arguments, remove
  unnecessary braces

Changes since V3:
* Use branch_get() instead of git_config_get_string() to look up branch
  configuration.
* Remove unnecessary string formatting in new error message in
  parse-options-cb.c.

Josh Steadmon (3):
  branch: accept multiple upstream branches for tracking
  branch: add flags and config to inherit tracking
  config: require lowercase for branch.*.autosetupmerge

 Documentation/config/branch.txt |   3 +-
 Documentation/git-branch.txt    |  24 ++--
 Documentation/git-checkout.txt  |   2 +-
 Documentation/git-switch.txt    |   2 +-
 branch.c                        | 189 ++++++++++++++++++++++++--------
 branch.h                        |   3 +-
 builtin/branch.c                |   6 +-
 builtin/checkout.c              |   6 +-
 config.c                        |   5 +-
 parse-options-cb.c              |  16 +++
 parse-options.h                 |   2 +
 t/t2017-checkout-orphan.sh      |  11 +-
 t/t2027-checkout-track.sh       |  23 ++++
 t/t2060-switch.sh               |  28 +++++
 t/t3200-branch.sh               |  39 ++++++-
 t/t7201-co.sh                   |  17 +++
 16 files changed, 310 insertions(+), 66 deletions(-)

Range-diff against v6:
1:  43d6f83fed ! 1:  9152367ba9 branch: accept multiple upstream branches for tracking
    @@ branch.c: static int should_setup_rebase(const char *origin)
     +	if (!remotes->nr)
     +		BUG("must provide at least one remote for branch config");
     +	if (rebasing && remotes->nr > 1)
    -+		die(_("cannot inherit upstream tracking configuration when rebasing is requested"));
    ++		die(_("cannot inherit upstream tracking configuration of "
    ++		      "multiple refs when rebasing is requested"));
     +
     +	if (!origin)
     +		for_each_string_list_item(item, remotes)
    @@ branch.c: int install_branch_config(int flag, const char *local, const char *ori
     -					  _("Branch '%s' set up to track local branch '%s'."),
     -					  local, shortname);
     +				strbuf_addf(&refname, "%s/", origin);
    -+			strbuf_addstr(&refname, remotes->items[0].string);
    ++			skip_prefix(remotes->items[0].string, "refs/heads/", &name);
    ++			strbuf_addstr(&refname, name);
     +
     +			/*
     +			 * Rebasing is only allowed in the case of a single
    @@ branch.c: int install_branch_config(int flag, const char *local, const char *ori
     +			origin ? origin : "",
     +			origin ? "/" : "",
     +			remotes->items[0].string);
    -+	else
    ++	else {
    ++		advise("  git config --add branch.\"%s\".remote %s",
    ++			local, origin ? origin : ".");
     +		for_each_string_list_item(item, remotes)
     +			advise("  git config --add branch.\"%s\".merge %s",
     +				local, item->string);
    ++	}
      
      	return -1;
      }
2:  57e57e6e6a ! 2:  afeb84539e branch: add flags and config to inherit tracking
    @@ branch.c: static void setup_tracking(const char *new_ref, const char *orig_ref,
      
     -	if (install_branch_config(config_flags, new_ref, tracking.remote,
     -			      tracking.src ? tracking.src : orig_ref) < 0)
    -+	if (tracking.srcs->nr < 1 && track != BRANCH_TRACK_INHERIT)
    ++	if (tracking.srcs->nr < 1)
     +		string_list_append(tracking.srcs, orig_ref);
    -+	if (install_branch_config_multiple_remotes(config_flags, new_ref, tracking.remote,
    -+			      tracking.srcs) < 0)
    ++	if (install_branch_config_multiple_remotes(config_flags, new_ref,
    ++				tracking.remote, tracking.srcs) < 0)
      		exit(-1);
      
     -	free(tracking.src);
    @@ t/t2027-checkout-track.sh: test_expect_success 'checkout --track -b rejects an e
     +test_expect_success 'checkout --track -b overrides autoSetupMerge=inherit' '
     +	# Set up tracking config on main
     +	test_config branch.main.remote origin &&
    -+	test_config branch.main.merge refs/heads/main &&
    ++	test_config branch.main.merge refs/heads/some-branch &&
     +	test_config branch.autoSetupMerge inherit &&
     +	# With --track=inherit, we copy the tracking config from main
     +	git checkout --track=inherit -b b1 main &&
     +	test_cmp_config origin branch.b1.remote &&
    -+	test_cmp_config refs/heads/main branch.b1.merge &&
    ++	test_cmp_config refs/heads/some-branch branch.b1.merge &&
     +	# With branch.autoSetupMerge=inherit, we do the same
     +	git checkout -b b2 main &&
     +	test_cmp_config origin branch.b2.remote &&
    -+	test_cmp_config refs/heads/main branch.b2.merge &&
    ++	test_cmp_config refs/heads/some-branch branch.b2.merge &&
     +	# But --track overrides this
     +	git checkout --track -b b3 main &&
     +	test_cmp_config . branch.b3.remote &&
3:  f79d27dc24 = 3:  a818a6561b config: require lowercase for branch.*.autosetupmerge

base-commit: 6c40894d2466d4e7fddc047a05116aa9d14712ee
-- 
2.34.1.173.g76aa8bc2d0-goog

Thanks! As noted in v6, I don't have strong opinions about omitting
'local/remote' from the help message, but I suspect others might. It
would be nice to get more opinions here.

v7 looks pretty good, it addresses all of the feedback on v6.
Unfortunately, I spotted some things _after_ you had already sent out v7
(my bad). That feedback is in [1].

We can ignore my feedback on 'simplifying' the conditional with a
format string. The more I think about it, the more impossible i18n
seems.

This just leaves the feedback on the message when inheriting from
multiple remote-tracking branches, i.e. prepending 'origin/' to the refs
in:

  branch 'main' set up to track from 'origin':
    main
    topic1
    topic2
 
[1] https://lore.kernel.org/git/kl6lzgovyvt7.fsf@chooglen-macbookpro.roam.corp.google.com (local)