repo::reservedname: test a submodule update

Test an initial submodule update, where we are trying to checkout
the submodule for the first time, and placing a file within the
submodule working directory with the same name as the submodule
(and consequently, the same name as the repository itself).

tests/repo/reservedname.c

@@ -106,3 +106,27 @@ void test_repo_reservedname__submodule_pointer(void)
 	git_repository_free(sub_repo);
 #endif
 }
+
+/* Like the `submodule_pointer` test (above), this ensures that we do not
+ * follow the gitlink to the submodule's repository location and treat that
+ * as a reserved name.  This tests at an initial submodule update, where the
+ * submodule repo is being created.
+ */
+void test_repo_reservedname__submodule_pointer_during_create(void)
+{
+	git_repository *repo;
+	git_submodule *sm;
+	git_submodule_update_options update_options = GIT_SUBMODULE_UPDATE_OPTIONS_INIT;
+	git_buf url = GIT_BUF_INIT;
+
+	repo = setup_fixture_super();
+
+	cl_git_pass(git_buf_joinpath(&url, clar_sandbox_path(), "sub.git"));
+	cl_repo_set_string(repo, "submodule.sub.url", url.ptr);
+
+	cl_git_pass(git_submodule_lookup(&sm, repo, "sub"));
+	cl_git_pass(git_submodule_update(sm, 1, &update_options));
+
+	git_submodule_free(sm);
+	git_buf_free(&url);
+}

tests/submodule/submodule_helpers.c

@@ -126,6 +126,22 @@ git_repository *setup_fixture_submod2(void)
 	return repo;
 }
 
+git_repository *setup_fixture_super(void)
+{
+	git_repository *repo = cl_git_sandbox_init("super");
+
+	cl_fixture_sandbox("sub.git");
+	p_mkdir("super/sub", 0777);
+
+	rewrite_gitmodules(git_repository_workdir(repo));
+
+	cl_set_cleanup(cleanup_fixture_submodules, "sub.git");
+
+	cl_git_pass(git_repository_reinit_filesystem(repo, 1));
+
+	return repo;
+}
+
 git_repository *setup_fixture_submodule_simple(void)
 {
 	git_repository *repo = cl_git_sandbox_init("submodule_simple");

tests/submodule/submodule_helpers.h

@@ -4,6 +4,7 @@ extern void rewrite_gitmodules(const char *workdir);
 extern git_repository *setup_fixture_submodules(void);
 extern git_repository *setup_fixture_submod2(void);
 extern git_repository *setup_fixture_submodule_simple(void);
+extern git_repository *setup_fixture_super(void);
 
 extern unsigned int get_submodule_status(git_repository *, const char *);