Add git_repository_reset_filesystem and fix tests

When a repository is transferred from one file system to another,
many of the config settings that represent the properties of the
file system may be wrong.  This adds a new public API that will
refresh the config settings of the repository to account for the
change of file system.  This doesn't do a full "reinitialize" and
operates on a existing git_repository object refreshing the config
when done.

This commit then makes use of the new API in clar as each test
repository is set up.

This commit also has a number of other clar test fixes where we
were making assumptions about the type of filesystem, either based
on outdated config data or based on the OS instead of the FS.

2 files changed, 73 insertions, 29 deletions

diff --git a/src/config.h b/src/config.h
index 85db5e3e1..01e8465cc 100644
--- a/src/config.h
+++ b/src/config.h
@@ -47,7 +47,7 @@ extern int git_config_rename_section(
  * @param out the new backend
  * @param path where the config file is located
  */
-extern int git_config_file__ondisk(struct git_config_backend **out, const char *path);
+extern int git_config_file__ondisk(git_config_backend **out, const char *path);
 
 extern int git_config__normalize_name(const char *in, char **out);
 
diff --git a/src/repository.c b/src/repository.c
index f609e5779..52509ffc1 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -962,34 +962,46 @@ static int create_empty_file(const char *path, mode_t mode)
 }
 
 static int repo_init_config(
+	git_config *parent,
 	const char *repo_dir,
 	const char *work_dir,
-	git_repository_init_options *opts)
+	uint32_t flags,
+	uint32_t mode)
 {
 	int error = 0;
-	git_buf cfg_path = GIT_BUF_INIT;
+	git_buf buf = GIT_BUF_INIT;
+	const char *cfg_path = NULL;
 	git_config *config = NULL;
-	bool is_bare = ((opts->flags & GIT_REPOSITORY_INIT_BARE) != 0);
+	bool is_bare = ((flags & GIT_REPOSITORY_INIT_BARE) != 0);
 
 #define SET_REPO_CONFIG(TYPE, NAME, VAL) do {\
 	if ((error = git_config_set_##TYPE(config, NAME, VAL)) < 0) \
 		goto cleanup; } while (0)
 
-	if (git_buf_joinpath(&cfg_path, repo_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
+	if (git_buf_joinpath(&buf, repo_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
 		return -1;
+	cfg_path = git_buf_cstr(&buf);
 
-	if (!git_path_isfile(git_buf_cstr(&cfg_path)) &&
-		create_empty_file(git_buf_cstr(&cfg_path), GIT_CONFIG_FILE_MODE) < 0) {
-			git_buf_free(&cfg_path);
-			return -1;
-	}
+	if (!git_path_isfile(cfg_path) &&
+		(error = create_empty_file(cfg_path, GIT_CONFIG_FILE_MODE)) < 0)
+		goto cleanup;
 
-	if (git_config_open_ondisk(&config, git_buf_cstr(&cfg_path)) < 0) {
-		git_buf_free(&cfg_path);
-		return -1;
+	if (!parent)
+		error = git_config_open_ondisk(&config, cfg_path);
+	else if ((error = git_config_open_level(
+		&config, parent, GIT_CONFIG_LEVEL_LOCAL)) < 0)
+	{
+		giterr_clear();
+
+		if (!(error = git_config_add_file_ondisk(
+				parent, cfg_path, GIT_CONFIG_LEVEL_LOCAL, false)))
+			error = git_config_open_level(
+				&config, parent, GIT_CONFIG_LEVEL_LOCAL);
 	}
+	if (error < 0)
+		goto cleanup;
 
-	if ((opts->flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0 &&
+	if ((flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0 &&
 		(error = check_repositoryformatversion(config)) < 0)
 		goto cleanup;
 
@@ -998,7 +1010,7 @@ static int repo_init_config(
 	SET_REPO_CONFIG(
 		int32, "core.repositoryformatversion", GIT_REPO_VERSION);
 	SET_REPO_CONFIG(
-		bool, "core.filemode", is_chmod_supported(git_buf_cstr(&cfg_path)));
+		bool, "core.filemode", is_chmod_supported(cfg_path));
 
 #ifdef GIT_USE_ICONV
 	SET_REPO_CONFIG(
@@ -1009,38 +1021,70 @@ static int repo_init_config(
 	if (!are_symlinks_supported(is_bare ? repo_dir : work_dir))
 		SET_REPO_CONFIG(bool, "core.symlinks", false);
 
+	/* core git does not do this on a reinit, but it is a property of
+	 * the filesystem, so I think we should...
+	 */
+	if (!(flags & GIT_REPOSITORY_INIT__IS_REINIT) &&
+		is_filesystem_case_insensitive(repo_dir))
+		SET_REPO_CONFIG(bool, "core.ignorecase", true);
+
 	if (!is_bare) {
 		SET_REPO_CONFIG(bool, "core.logallrefupdates", true);
 
-		if (!(opts->flags & GIT_REPOSITORY_INIT__NATURAL_WD)) {
+		if (!(flags & GIT_REPOSITORY_INIT__NATURAL_WD)) {
 			SET_REPO_CONFIG(string, "core.worktree", work_dir);
 		}
-		else if ((opts->flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0) {
+		else if ((flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0) {
 			if (git_config_delete_entry(config, "core.worktree") < 0)
 				giterr_clear();
 		}
 	}
 
-	if (!(opts->flags & GIT_REPOSITORY_INIT__IS_REINIT) &&
-		is_filesystem_case_insensitive(repo_dir))
-		SET_REPO_CONFIG(bool, "core.ignorecase", true);
-
-	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_GROUP) {
+	if (mode == GIT_REPOSITORY_INIT_SHARED_GROUP) {
 		SET_REPO_CONFIG(int32, "core.sharedrepository", 1);
 		SET_REPO_CONFIG(bool, "receive.denyNonFastforwards", true);
 	}
-	else if (opts->mode == GIT_REPOSITORY_INIT_SHARED_ALL) {
+	else if (mode == GIT_REPOSITORY_INIT_SHARED_ALL) {
 		SET_REPO_CONFIG(int32, "core.sharedrepository", 2);
 		SET_REPO_CONFIG(bool, "receive.denyNonFastforwards", true);
 	}
 
 cleanup:
-	git_buf_free(&cfg_path);
+	git_buf_free(&buf);
 	git_config_free(config);
 
 	return error;
 }
 
+int git_repository_reset_filesystem(git_repository *repo)
+{
+	int error = 0;
+	uint32_t flags = 0;
+	const char *repo_dir, *work_dir;
+	git_config *cfg;
+
+	assert(repo);
+
+	repo_dir = git_repository_path(repo);
+	work_dir = git_repository_workdir(repo);
+
+	if (git_repository_is_bare(repo))
+		flags |= GIT_REPOSITORY_INIT_BARE;
+	else if (!git__prefixcmp(repo_dir, work_dir) &&
+		!strcmp(repo_dir + strlen(work_dir), DOT_GIT "/"))
+		flags |= GIT_REPOSITORY_INIT__NATURAL_WD;
+
+	if ((error = git_repository_config(&cfg, repo)) < 0)
+		return error;
+
+	error = repo_init_config(cfg, repo_dir, work_dir, flags, 0);
+
+	git_config_free(cfg);
+	git_repository__cvar_cache_clear(repo);
+
+	return error;
+}
+
 static int repo_write_template(
 	const char *git_dir,
 	bool allow_overwrite,
@@ -1429,22 +1473,22 @@ int git_repository_init_ext(
 		opts->flags |= GIT_REPOSITORY_INIT__IS_REINIT;
 
 		error = repo_init_config(
-			git_buf_cstr(&repo_path), git_buf_cstr(&wd_path), opts);
+			NULL, repo_path.ptr, wd_path.ptr, opts->flags, opts->mode);
 
 		/* TODO: reinitialize the templates */
 	}
 	else {
 		if (!(error = repo_init_structure(
-				git_buf_cstr(&repo_path), git_buf_cstr(&wd_path), opts)) &&
+				repo_path.ptr, wd_path.ptr, opts)) &&
 			!(error = repo_init_config(
-				git_buf_cstr(&repo_path), git_buf_cstr(&wd_path), opts)))
+				NULL, repo_path.ptr, wd_path.ptr, opts->flags, opts->mode)))
 			error = repo_init_create_head(
-				git_buf_cstr(&repo_path), opts->initial_head);
+				repo_path.ptr, opts->initial_head);
 	}
 	if (error < 0)
 		goto cleanup;
 
-	error = git_repository_open(out, git_buf_cstr(&repo_path));
+	error = git_repository_open(out, repo_path.ptr);
 
 	if (!error && opts->origin_url)
 		error = repo_init_create_origin(*out, opts->origin_url);