repository: do not initialize HEAD if it's provided by templates

When using templates to initialize a git repository, then git-init(1)
will copy over all contents of the template directory. These will be
preferred over the default ones created by git-init(1). While we mostly
do the same, there is the exception of "HEAD". While we do copy over the
template's HEAD file, afterwards we'll immediately re-initialize its
contents with either the default "ref: refs/origin/master" or the init
option's `initial_head` field.

Let's fix the inconsistency with upstream git-init(1) by not overwriting
the template HEAD, but only if the user hasn't set `opts.initial_head`.
If the `initial_head` field has been supplied, we should use that
indifferent from whether the template contained a HEAD file or not. Add
tests to verify we correctly use the template directory's HEAD file and
that `initial_head` overrides the template.

1 files changed, 35 insertions, 0 deletions

diff --git a/tests/repo/template.c b/tests/repo/template.c
index e86582ac3..7ccd93521 100644
--- a/tests/repo/template.c
+++ b/tests/repo/template.c
@@ -249,6 +249,41 @@ void test_repo_template__extended_with_template_and_shared_mode(void)
 	validate_templates(_repo, "template");
 }
 
+void test_repo_template__templated_head_is_used(void)
+{
+	git_repository_init_options opts = GIT_REPOSITORY_INIT_OPTIONS_INIT;
+	git_buf head = GIT_BUF_INIT;
+
+	opts.flags = GIT_REPOSITORY_INIT_MKPATH | GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE;
+
+	setup_templates("template", true);
+	cl_git_mkfile("template/HEAD", "foobar\n");
+	setup_repo("repo", &opts);
+
+	cl_git_pass(git_futils_readbuffer(&head, "repo/.git/HEAD"));
+	cl_assert_equal_s("foobar\n", head.ptr);
+
+	git_buf_dispose(&head);
+}
+
+void test_repo_template__initial_head_option_overrides_template_head(void)
+{
+	git_repository_init_options opts = GIT_REPOSITORY_INIT_OPTIONS_INIT;
+	git_buf head = GIT_BUF_INIT;
+
+	opts.flags = GIT_REPOSITORY_INIT_MKPATH | GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE;
+	opts.initial_head = "manual";
+
+	setup_templates("template", true);
+	cl_git_mkfile("template/HEAD", "foobar\n");
+	setup_repo("repo", &opts);
+
+	cl_git_pass(git_futils_readbuffer(&head, "repo/.git/HEAD"));
+	cl_assert_equal_s("ref: refs/heads/manual\n", head.ptr);
+
+	git_buf_dispose(&head);
+}
+
 void test_repo_template__empty_template_path(void)
 {
 	git_repository_init_options opts = GIT_REPOSITORY_INIT_OPTIONS_INIT;