t12-repo.c ported, although kind of messy.

It'd be nice to be rid of all the #define's, but converting to const
char*'s would be even messier, and less declarative.

tests-clar/repo/discover.c

+#include "clar_libgit2.h"
+
+#include "odb.h"
+#include "repository.h"
+
+
+#define TEMP_REPO_FOLDER "temprepo/"
+#define DISCOVER_FOLDER TEMP_REPO_FOLDER "discover.git"
+
+#define SUB_REPOSITORY_FOLDER_NAME "sub_repo"
+#define SUB_REPOSITORY_FOLDER DISCOVER_FOLDER "/" SUB_REPOSITORY_FOLDER_NAME
+#define SUB_REPOSITORY_FOLDER_SUB SUB_REPOSITORY_FOLDER "/sub"
+#define SUB_REPOSITORY_FOLDER_SUB_SUB SUB_REPOSITORY_FOLDER_SUB "/subsub"
+#define SUB_REPOSITORY_FOLDER_SUB_SUB_SUB SUB_REPOSITORY_FOLDER_SUB_SUB "/subsubsub"
+
+#define REPOSITORY_ALTERNATE_FOLDER DISCOVER_FOLDER "/alternate_sub_repo"
+#define REPOSITORY_ALTERNATE_FOLDER_SUB REPOSITORY_ALTERNATE_FOLDER "/sub"
+#define REPOSITORY_ALTERNATE_FOLDER_SUB_SUB REPOSITORY_ALTERNATE_FOLDER_SUB "/subsub"
+#define REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB REPOSITORY_ALTERNATE_FOLDER_SUB_SUB "/subsubsub"
+
+#define ALTERNATE_MALFORMED_FOLDER1 DISCOVER_FOLDER "/alternate_malformed_repo1"
+#define ALTERNATE_MALFORMED_FOLDER2 DISCOVER_FOLDER "/alternate_malformed_repo2"
+#define ALTERNATE_MALFORMED_FOLDER3 DISCOVER_FOLDER "/alternate_malformed_repo3"
+#define ALTERNATE_NOT_FOUND_FOLDER DISCOVER_FOLDER "/alternate_not_found_repo"
+
+static int ensure_repository_discover(const char *start_path, const char *ceiling_dirs, const char *expected_path)
+{
+	int error;
+	char found_path[GIT_PATH_MAX];
+
+	error = git_repository_discover(found_path, sizeof(found_path), start_path, 0, ceiling_dirs);
+	//across_fs is always 0 as we can't automate the filesystem change tests
+
+	if (error < GIT_SUCCESS)
+		return error;
+
+	return strcmp(found_path, expected_path) ? GIT_ERROR : GIT_SUCCESS;
+}
+
+static int write_file(const char *path, const char *content)
+{
+	int error;
+	git_file file;
+
+	if (git_path_exists(path) == GIT_SUCCESS) {
+		error = p_unlink(path);
+
+		if (error < GIT_SUCCESS)
+			return error;
+	}
+
+	file = git_futils_creat_withpath(path, 0777, 0666);
+	if (file < GIT_SUCCESS)
+		return file;
+
+	error = p_write(file, content, strlen(content) * sizeof(char));
+
+	p_close(file);
+
+	return error;
+}
+
+//no check is performed on ceiling_dirs length, so be sure it's long enough
+static int append_ceiling_dir(git_buf *ceiling_dirs, const char *path)
+{
+	git_buf pretty_path = GIT_BUF_INIT;
+	int error;
+	char ceiling_separator[2] = { GIT_PATH_LIST_SEPARATOR, '\0' };
+
+	error = git_path_prettify_dir(&pretty_path, path, NULL);
+	if (error < GIT_SUCCESS)
+		return git__rethrow(error, "Failed to append ceiling directory.");
+
+	if (ceiling_dirs->size > 0)
+		git_buf_puts(ceiling_dirs, ceiling_separator);
+	git_buf_puts(ceiling_dirs, pretty_path.ptr);
+
+	git_buf_free(&pretty_path);
+
+	return git_buf_lasterror(ceiling_dirs);
+}
+
+void test_repo_discover__0(void)
+{
+   // test discover
+	git_repository *repo;
+	git_buf ceiling_dirs_buf = GIT_BUF_INIT;
+	const char *ceiling_dirs;
+	char repository_path[GIT_PATH_MAX];
+	char sub_repository_path[GIT_PATH_MAX];
+	char found_path[GIT_PATH_MAX];
+	const mode_t mode = 0777;
+
+	git_futils_mkdir_r(DISCOVER_FOLDER, NULL, mode);
+	cl_git_pass(append_ceiling_dir(&ceiling_dirs_buf, TEMP_REPO_FOLDER));
+	ceiling_dirs = git_buf_cstr(&ceiling_dirs_buf);
+
+	cl_assert(git_repository_discover(repository_path, sizeof(repository_path), DISCOVER_FOLDER, 0, ceiling_dirs) == GIT_ENOTAREPO);
+
+	cl_git_pass(git_repository_init(&repo, DISCOVER_FOLDER, 1));
+	cl_git_pass(git_repository_discover(repository_path, sizeof(repository_path), DISCOVER_FOLDER, 0, ceiling_dirs));
+	git_repository_free(repo);
+
+	cl_git_pass(git_repository_init(&repo, SUB_REPOSITORY_FOLDER, 0));
+	cl_git_pass(git_futils_mkdir_r(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, NULL, mode));
+	cl_git_pass(git_repository_discover(sub_repository_path, sizeof(sub_repository_path), SUB_REPOSITORY_FOLDER, 0, ceiling_dirs));
+
+	cl_git_pass(git_futils_mkdir_r(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, NULL, mode));
+	cl_git_pass(ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB_SUB, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, ceiling_dirs, sub_repository_path));
+
+	cl_git_pass(git_futils_mkdir_r(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, NULL, mode));
+	cl_git_pass(write_file(REPOSITORY_ALTERNATE_FOLDER "/" DOT_GIT, "gitdir: ../" SUB_REPOSITORY_FOLDER_NAME "/" DOT_GIT));
+	cl_git_pass(write_file(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB "/" DOT_GIT, "gitdir: ../../../" SUB_REPOSITORY_FOLDER_NAME "/" DOT_GIT));
+	cl_git_pass(write_file(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB "/" DOT_GIT, "gitdir: ../../../../"));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, ceiling_dirs, repository_path));
+
+	cl_git_pass(git_futils_mkdir_r(ALTERNATE_MALFORMED_FOLDER1, NULL, mode));
+	cl_git_pass(write_file(ALTERNATE_MALFORMED_FOLDER1 "/" DOT_GIT, "Anything but not gitdir:"));
+	cl_git_pass(git_futils_mkdir_r(ALTERNATE_MALFORMED_FOLDER2, NULL, mode));
+	cl_git_pass(write_file(ALTERNATE_MALFORMED_FOLDER2 "/" DOT_GIT, "gitdir:"));
+	cl_git_pass(git_futils_mkdir_r(ALTERNATE_MALFORMED_FOLDER3, NULL, mode));
+	cl_git_pass(write_file(ALTERNATE_MALFORMED_FOLDER3 "/" DOT_GIT, "gitdir: \n\n\n"));
+	cl_git_pass(git_futils_mkdir_r(ALTERNATE_NOT_FOUND_FOLDER, NULL, mode));
+	cl_git_pass(write_file(ALTERNATE_NOT_FOUND_FOLDER "/" DOT_GIT, "gitdir: a_repository_that_surely_does_not_exist"));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), ALTERNATE_MALFORMED_FOLDER1, 0, ceiling_dirs));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), ALTERNATE_MALFORMED_FOLDER2, 0, ceiling_dirs));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), ALTERNATE_MALFORMED_FOLDER3, 0, ceiling_dirs));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), ALTERNATE_NOT_FOUND_FOLDER, 0, ceiling_dirs));
+
+	cl_git_pass(append_ceiling_dir(&ceiling_dirs_buf, SUB_REPOSITORY_FOLDER));
+	ceiling_dirs = git_buf_cstr(&ceiling_dirs_buf);
+
+	//this must pass as ceiling_directories cannot predent the current
+	//working directory to be checked
+	cl_git_pass(git_repository_discover(found_path, sizeof(found_path), SUB_REPOSITORY_FOLDER, 0, ceiling_dirs));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), SUB_REPOSITORY_FOLDER_SUB, 0, ceiling_dirs));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), SUB_REPOSITORY_FOLDER_SUB_SUB, 0, ceiling_dirs));
+	cl_git_fail(git_repository_discover(found_path, sizeof(found_path), SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, 0, ceiling_dirs));
+
+	//.gitfile redirection should not be affected by ceiling directories
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB, ceiling_dirs, sub_repository_path));
+	cl_git_pass(ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, ceiling_dirs, repository_path));
+
+	cl_git_pass(git_futils_rmdir_r(TEMP_REPO_FOLDER, 1));
+	git_repository_free(repo);
+	git_buf_free(&ceiling_dirs_buf);
+}
+