init: provide useful advice about init.defaultBranch

To give ample warning for users wishing to override Git's the fall-back
for an unconfigured `init.defaultBranch` (in case we decide to change it
in a future Git version), let's introduce some advice that is shown upon
`git init` when that value is not set.

Note: two test cases in Git's test suite want to verify that the
`stderr` output of `git init` is empty. It is now necessary to suppress
the advice, we now do that via the `init.defaultBranch` setting. While
not strictly necessary, we also set this to `false` in
`test_create_repo()`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/refs.c b/refs.c
index 8df03122d6..13dc2c3291 100644
--- a/refs.c
+++ b/refs.c
@@ -562,6 +562,19 @@ void expand_ref_prefix(struct strvec *prefixes, const char *prefix)
 		strvec_pushf(prefixes, *p, len, prefix);
 }
 
+static const char default_branch_name_advice[] = N_(
+"Using '%s' as the name for the initial branch. This default branch name\n"
+"is subject to change. To configure the initial branch name to use in all\n"
+"of your new repositories, which will suppress this warning, call:\n"
+"\n"
+"\tgit config --global init.defaultBranch <name>\n"
+"\n"
+"Names commonly chosen instead of 'master' are 'main', 'trunk' and\n"
+"'development'. The just-created branch can be renamed via this command:\n"
+"\n"
+"\tgit branch -m <name>\n"
+);
+
 char *repo_default_branch_name(struct repository *r, int quiet)
 {
 	const char *config_key = "init.defaultbranch";
@@ -574,8 +587,11 @@ char *repo_default_branch_name(struct repository *r, int quiet)
 	else if (repo_config_get_string(r, config_key, &ret) < 0)
 		die(_("could not retrieve `%s`"), config_display_key);
 
-	if (!ret)
+	if (!ret) {
 		ret = xstrdup("master");
+		if (!quiet)
+			advise(_(default_branch_name_advice), ret);
+	}
 
 	full_ref = xstrfmt("refs/heads/%s", ret);
 	if (check_refname_format(full_ref, 0))