More filemode cleanups for FAT on MacOS

This cleans up some additional issues.  The main change is that
on a filesystem that doesn't support mode bits, libgit2 will now
create new blobs with GIT_FILEMODE_BLOB always instead of being
at the mercy to the filesystem driver to report executable or not.
This means that if "core.filemode" lies and claims that filemode
is not supported, then we will ignore the executable bit from the
filesystem.  Previously we would have allowed it.

This adds an option to the new git_repository_reset_filesystem to
recurse through submodules if desired.  There may be other types
of APIs that would like a "recurse submodules" option, but this
one is particularly useful.

This also has a number of cleanups, etc., for related things
including trying to give better error messages when problems come
up from the filesystem.  For example, the FAT filesystem driver on
MacOS appears to return errno EINVAL if you attempt to write a
filename with invalid UTF-8 in it.  We try to capture that with a
better error message now.

1 files changed, 116 insertions, 69 deletions

diff --git a/src/repository.c b/src/repository.c
index 52509ffc1..23cafe05a 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -961,80 +961,121 @@ static int create_empty_file(const char *path, mode_t mode)
 	return 0;
 }
 
-static int repo_init_config(
-	git_config *parent,
-	const char *repo_dir,
-	const char *work_dir,
-	uint32_t flags,
-	uint32_t mode)
+static int repo_local_config(
+	git_config **out,
+	git_buf *config_dir,
+	git_repository *repo,
+	const char *repo_dir)
 {
 	int error = 0;
-	git_buf buf = GIT_BUF_INIT;
-	const char *cfg_path = NULL;
-	git_config *config = NULL;
-	bool is_bare = ((flags & GIT_REPOSITORY_INIT_BARE) != 0);
+	git_config *parent;
+	const char *cfg_path;
 
-#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(&buf, repo_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
+	if (git_buf_joinpath(config_dir, repo_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
 		return -1;
-	cfg_path = git_buf_cstr(&buf);
+	cfg_path = git_buf_cstr(config_dir);
 
+	/* make LOCAL config if missing */
 	if (!git_path_isfile(cfg_path) &&
 		(error = create_empty_file(cfg_path, GIT_CONFIG_FILE_MODE)) < 0)
-		goto cleanup;
+		return error;
 
-	if (!parent)
-		error = git_config_open_ondisk(&config, cfg_path);
-	else if ((error = git_config_open_level(
-		&config, parent, GIT_CONFIG_LEVEL_LOCAL)) < 0)
-	{
+	/* if no repo, just open that file directly */
+	if (!repo)
+		return git_config_open_ondisk(out, cfg_path);
+
+	/* otherwise, open parent config and get that level */
+	if ((error = git_repository_config__weakptr(&parent, repo)) < 0)
+		return error;
+
+	if (git_config_open_level(out, 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);
+			error = git_config_open_level(out, parent, GIT_CONFIG_LEVEL_LOCAL);
 	}
-	if (error < 0)
-		goto cleanup;
 
-	if ((flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0 &&
-		(error = check_repositoryformatversion(config)) < 0)
-		goto cleanup;
+	git_config_free(parent);
+
+	return error;
+}
+
+static int repo_init_fs_configs(
+	git_config *cfg,
+	const char *cfg_path,
+	const char *repo_dir,
+	const char *work_dir,
+	bool update_ignorecase)
+{
+	int error = 0;
+
+	if (!work_dir)
+		work_dir = repo_dir;
+
+	if ((error = git_config_set_bool(
+			cfg, "core.filemode", is_chmod_supported(cfg_path))) < 0)
+		return error;
+
+	if (!are_symlinks_supported(work_dir)) {
+		if ((error = git_config_set_bool(cfg, "core.symlinks", false)) < 0)
+			return error;
+	} else if (git_config_delete_entry(cfg, "core.symlinks") < 0)
+		giterr_clear();
 
-	SET_REPO_CONFIG(
-		bool, "core.bare", is_bare);
-	SET_REPO_CONFIG(
-		int32, "core.repositoryformatversion", GIT_REPO_VERSION);
-	SET_REPO_CONFIG(
-		bool, "core.filemode", is_chmod_supported(cfg_path));
+	if (update_ignorecase) {
+		if (is_filesystem_case_insensitive(repo_dir)) {
+			if ((error = git_config_set_bool(cfg, "core.ignorecase", true)) < 0)
+				return error;
+		} else if (git_config_delete_entry(cfg, "core.ignorecase") < 0)
+			giterr_clear();
+	}
 
 #ifdef GIT_USE_ICONV
-	SET_REPO_CONFIG(
-		bool, "core.precomposeunicode",
-		does_fs_decompose_unicode_paths(is_bare ? repo_dir : work_dir));
+	if ((error = git_config_set_bool(
+			cfg, "core.precomposeunicode",
+			does_fs_decompose_unicode_paths(work_dir))) < 0)
+		return error;
 #endif
 
-	if (!are_symlinks_supported(is_bare ? repo_dir : work_dir))
-		SET_REPO_CONFIG(bool, "core.symlinks", false);
+	return 0;
+}
 
-	/* 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);
+static int repo_init_config(
+	const char *repo_dir,
+	const char *work_dir,
+	uint32_t flags,
+	uint32_t mode)
+{
+	int error = 0;
+	git_buf cfg_path = GIT_BUF_INIT;
+	git_config *config = NULL;
+	bool is_bare = ((flags & GIT_REPOSITORY_INIT_BARE) != 0);
+	bool is_reinit = ((flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0);
+
+	if ((error = repo_local_config(&config, &cfg_path, NULL, repo_dir)) < 0)
+		goto cleanup;
+
+	if (is_reinit && (error = check_repositoryformatversion(config)) < 0)
+		goto cleanup;
+
+#define SET_REPO_CONFIG(TYPE, NAME, VAL) do { \
+	if ((error = git_config_set_##TYPE(config, NAME, VAL)) < 0) \
+		goto cleanup; } while (0)
+
+	SET_REPO_CONFIG(bool, "core.bare", is_bare);
+	SET_REPO_CONFIG(int32, "core.repositoryformatversion", GIT_REPO_VERSION);
+
+	if ((error = repo_init_fs_configs(
+			config, cfg_path.ptr, repo_dir, work_dir, !is_reinit)) < 0)
+		goto cleanup;
 
 	if (!is_bare) {
 		SET_REPO_CONFIG(bool, "core.logallrefupdates", true);
 
-		if (!(flags & GIT_REPOSITORY_INIT__NATURAL_WD)) {
+		if (!(flags & GIT_REPOSITORY_INIT__NATURAL_WD))
 			SET_REPO_CONFIG(string, "core.worktree", work_dir);
-		}
-		else if ((flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0) {
+		else if (is_reinit) {
 			if (git_config_delete_entry(config, "core.worktree") < 0)
 				giterr_clear();
 		}
@@ -1050,38 +1091,44 @@ static int repo_init_config(
 	}
 
 cleanup:
-	git_buf_free(&buf);
+	git_buf_free(&cfg_path);
 	git_config_free(config);
 
 	return error;
 }
 
-int git_repository_reset_filesystem(git_repository *repo)
+static int repo_reset_submodule_fs(git_submodule *sm, const char *n, void *p)
 {
-	int error = 0;
-	uint32_t flags = 0;
-	const char *repo_dir, *work_dir;
-	git_config *cfg;
+	git_repository *smrepo = NULL;
+	GIT_UNUSED(n); GIT_UNUSED(p);
 
-	assert(repo);
+	if (git_submodule_open(&smrepo, sm) < 0 ||
+		git_repository_reset_filesystem(smrepo, true) < 0)
+		giterr_clear();
+	git_repository_free(smrepo);
 
-	repo_dir = git_repository_path(repo);
-	work_dir = git_repository_workdir(repo);
+	return 0;
+}
 
-	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;
+int git_repository_reset_filesystem(git_repository *repo, int recurse)
+{
+	int error = 0;
+	git_buf path = GIT_BUF_INIT;
+	git_config *config = NULL;
+	const char *repo_dir = git_repository_path(repo);
 
-	if ((error = git_repository_config(&cfg, repo)) < 0)
-		return error;
+	if (!(error = repo_local_config(&config, &path, repo, repo_dir)))
+		error = repo_init_fs_configs(
+			config, path.ptr, repo_dir, git_repository_workdir(repo), true);
 
-	error = repo_init_config(cfg, repo_dir, work_dir, flags, 0);
+	git_config_free(config);
+	git_buf_free(&path);
 
-	git_config_free(cfg);
 	git_repository__cvar_cache_clear(repo);
 
+	if (!repo->is_bare && recurse)
+		(void)git_submodule_foreach(repo, repo_reset_submodule_fs, NULL);
+
 	return error;
 }
 
@@ -1473,7 +1520,7 @@ int git_repository_init_ext(
 		opts->flags |= GIT_REPOSITORY_INIT__IS_REINIT;
 
 		error = repo_init_config(
-			NULL, repo_path.ptr, wd_path.ptr, opts->flags, opts->mode);
+			repo_path.ptr, wd_path.ptr, opts->flags, opts->mode);
 
 		/* TODO: reinitialize the templates */
 	}
@@ -1481,7 +1528,7 @@ int git_repository_init_ext(
 		if (!(error = repo_init_structure(
 				repo_path.ptr, wd_path.ptr, opts)) &&
 			!(error = repo_init_config(
-				NULL, repo_path.ptr, wd_path.ptr, opts->flags, opts->mode)))
+				repo_path.ptr, wd_path.ptr, opts->flags, opts->mode)))
 			error = repo_init_create_head(
 				repo_path.ptr, opts->initial_head);
 	}