Merge branch 'ps/reflog-list' into HEAD

"git reflog" learned a "list" subcommand that enumerates known reflogs.

* ps/reflog-list:
  builtin/reflog: introduce subcommand to list reflogs
  refs: stop resolving ref corresponding to reflogs
  refs: drop unused params from the reflog iterator callback
  refs: always treat iterators as ordered
  refs/files: sort merged worktree and common reflogs
  refs/files: sort reflogs returned by the reflog iterator
  dir-iterator: support iteration in sorted order
  dir-iterator: pass name to `prepare_next_entry_data()` directly

Documentation/git-reflog.txt

@@ -10,6 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git reflog' [show] [<log-options>] [<ref>]
+'git reflog list'
 'git reflog expire' [--expire=<time>] [--expire-unreachable=<time>]
 	[--rewrite] [--updateref] [--stale-fix]
 	[--dry-run | -n] [--verbose] [--all [--single-worktree] | <refs>...]
@@ -39,6 +40,8 @@ actions, and in addition the `HEAD` reflog records branch switching.
 `git reflog show` is an alias for `git log -g --abbrev-commit
 --pretty=oneline`; see linkgit:git-log[1] for more information.
 
+The "list" subcommand lists all refs which have a corresponding reflog.
+
 The "expire" subcommand prunes older reflog entries. Entries older
 than `expire` time, or entries older than `expire-unreachable` time
 and not reachable from the current tip, are removed from the reflog.

builtin/fsck.c

@@ -509,9 +509,7 @@ static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid
 	return 0;
 }
 
-static int fsck_handle_reflog(const char *logname,
+static int fsck_handle_reflog(const char *logname, void *cb_data)
-			      const struct object_id *oid UNUSED,
-			      int flag UNUSED, void *cb_data)
 {
 	struct strbuf refname = STRBUF_INIT;
 

builtin/reflog.c

@@ -7,11 +7,15 @@
 #include "wildmatch.h"
 #include "worktree.h"
 #include "reflog.h"
+#include "refs.h"
 #include "parse-options.h"
 
 #define BUILTIN_REFLOG_SHOW_USAGE \
 	N_("git reflog [show] [<log-options>] [<ref>]")
 
+#define BUILTIN_REFLOG_LIST_USAGE \
+	N_("git reflog list")
+
 #define BUILTIN_REFLOG_EXPIRE_USAGE \
 	N_("git reflog expire [--expire=<time>] [--expire-unreachable=<time>]\n" \
 	   "                  [--rewrite] [--updateref] [--stale-fix]\n" \
@@ -29,6 +33,11 @@ static const char *const reflog_show_usage[] = {
 	NULL,
 };
 
+static const char *const reflog_list_usage[] = {
+	BUILTIN_REFLOG_LIST_USAGE,
+	NULL,
+};
+
 static const char *const reflog_expire_usage[] = {
 	BUILTIN_REFLOG_EXPIRE_USAGE,
 	NULL
@@ -46,6 +55,7 @@ static const char *const reflog_exists_usage[] = {
 
 static const char *const reflog_usage[] = {
 	BUILTIN_REFLOG_SHOW_USAGE,
+	BUILTIN_REFLOG_LIST_USAGE,
 	BUILTIN_REFLOG_EXPIRE_USAGE,
 	BUILTIN_REFLOG_DELETE_USAGE,
 	BUILTIN_REFLOG_EXISTS_USAGE,
@@ -60,8 +70,7 @@ struct worktree_reflogs {
 	struct string_list reflogs;
 };
 
-static int collect_reflog(const char *ref, const struct object_id *oid UNUSED,
+static int collect_reflog(const char *ref, void *cb_data)
-			  int flags UNUSED, void *cb_data)
 {
 	struct worktree_reflogs *cb = cb_data;
 	struct worktree *worktree = cb->worktree;
@@ -238,6 +247,29 @@ static int cmd_reflog_show(int argc, const char **argv, const char *prefix)
 	return cmd_log_reflog(argc, argv, prefix);
 }
 
+static int show_reflog(const char *refname, void *cb_data UNUSED)
+{
+	printf("%s\n", refname);
+	return 0;
+}
+
+static int cmd_reflog_list(int argc, const char **argv, const char *prefix)
+{
+	struct option options[] = {
+		OPT_END()
+	};
+	struct ref_store *ref_store;
+
+	argc = parse_options(argc, argv, prefix, options, reflog_list_usage, 0);
+	if (argc)
+		return error(_("%s does not accept arguments: '%s'"),
+			     "list", argv[0]);
+
+	ref_store = get_main_ref_store(the_repository);
+
+	return refs_for_each_reflog(ref_store, show_reflog, NULL);
+}
+
 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 {
 	struct cmd_reflog_expire_cb cmd = { 0 };
@@ -417,6 +449,7 @@ int cmd_reflog(int argc, const char **argv, const char *prefix)
 	parse_opt_subcommand_fn *fn = NULL;
 	struct option options[] = {
 		OPT_SUBCOMMAND("show", &fn, cmd_reflog_show),
+		OPT_SUBCOMMAND("list", &fn, cmd_reflog_list),
 		OPT_SUBCOMMAND("expire", &fn, cmd_reflog_expire),
 		OPT_SUBCOMMAND("delete", &fn, cmd_reflog_delete),
 		OPT_SUBCOMMAND("exists", &fn, cmd_reflog_exists),

dir-iterator.c

@@ -2,10 +2,19 @@
 #include "dir.h"
 #include "iterator.h"
 #include "dir-iterator.h"
+#include "string-list.h"
 
 struct dir_iterator_level {
 	DIR *dir;
 
+	/*
+	 * The directory entries of the current level. This list will only be
+	 * populated when the iterator is ordered. In that case, `dir` will be
+	 * set to `NULL`.
+	 */
+	struct string_list entries;
+	size_t entries_idx;
+
 	/*
 	 * The length of the directory part of path at this level
 	 * (including a trailing '/'):
@@ -43,6 +52,31 @@ struct dir_iterator_int {
 	unsigned int flags;
 };
 
+static int next_directory_entry(DIR *dir, const char *path,
+				struct dirent **out)
+{
+	struct dirent *de;
+
+repeat:
+	errno = 0;
+	de = readdir(dir);
+	if (!de) {
+		if (errno) {
+			warning_errno("error reading directory '%s'",
+				      path);
+			return -1;
+		}
+
+		return 1;
+	}
+
+	if (is_dot_or_dotdot(de->d_name))
+		goto repeat;
+
+	*out = de;
+	return 0;
+}
+
 /*
  * Push a level in the iter stack and initialize it with information from
  * the directory pointed by iter->base->path. It is assumed that this
@@ -72,6 +106,35 @@ static int push_level(struct dir_iterator_int *iter)
 		return -1;
 	}
 
+	string_list_init_dup(&level->entries);
+	level->entries_idx = 0;
+
+	/*
+	 * When the iterator is sorted we read and sort all directory entries
+	 * directly.
+	 */
+	if (iter->flags & DIR_ITERATOR_SORTED) {
+		struct dirent *de;
+
+		while (1) {
+			int ret = next_directory_entry(level->dir, iter->base.path.buf, &de);
+			if (ret < 0) {
+				if (errno != ENOENT &&
+				    iter->flags & DIR_ITERATOR_PEDANTIC)
+					return -1;
+				continue;
+			} else if (ret > 0) {
+				break;
+			}
+
+			string_list_append(&level->entries, de->d_name);
+		}
+		string_list_sort(&level->entries);
+
+		closedir(level->dir);
+		level->dir = NULL;
+	}
+
 	return 0;
 }
 
@@ -88,21 +151,22 @@ static int pop_level(struct dir_iterator_int *iter)
 		warning_errno("error closing directory '%s'",
 			      iter->base.path.buf);
 	level->dir = NULL;
+	string_list_clear(&level->entries, 0);
 
 	return --iter->levels_nr;
 }
 
 /*
  * Populate iter->base with the necessary information on the next iteration
- * entry, represented by the given dirent de. Return 0 on success and -1
+ * entry, represented by the given name. Return 0 on success and -1
  * otherwise, setting errno accordingly.
  */
 static int prepare_next_entry_data(struct dir_iterator_int *iter,
-				   struct dirent *de)
+				   const char *name)
 {
 	int err, saved_errno;
 
-	strbuf_addstr(&iter->base.path, de->d_name);
+	strbuf_addstr(&iter->base.path, name);
 	/*
 	 * We have to reset these because the path strbuf might have
 	 * been realloc()ed at the previous strbuf_addstr().
@@ -139,27 +203,34 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
 		struct dirent *de;
 		struct dir_iterator_level *level =
 			&iter->levels[iter->levels_nr - 1];
+		const char *name;
 
 		strbuf_setlen(&iter->base.path, level->prefix_len);
-		errno = 0;
-		de = readdir(level->dir);
 
-		if (!de) {
+		if (level->dir) {
-			if (errno) {
+			int ret = next_directory_entry(level->dir, iter->base.path.buf, &de);
-				warning_errno("error reading directory '%s'",
+			if (ret < 0) {
-					      iter->base.path.buf);
 				if (iter->flags & DIR_ITERATOR_PEDANTIC)
 					goto error_out;
-			} else if (pop_level(iter) == 0) {
+				continue;
+			} else if (ret > 0) {
+				if (pop_level(iter) == 0)
 					return dir_iterator_abort(dir_iterator);
-			}
 				continue;
 			}
 
-		if (is_dot_or_dotdot(de->d_name))
+			name = de->d_name;
+		} else {
+			if (level->entries_idx >= level->entries.nr) {
+				if (pop_level(iter) == 0)
+					return dir_iterator_abort(dir_iterator);
 				continue;
+			}
 
-		if (prepare_next_entry_data(iter, de)) {
+			name = level->entries.items[level->entries_idx++].string;
+		}
+
+		if (prepare_next_entry_data(iter, name)) {
 			if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
 				goto error_out;
 			continue;
@@ -188,6 +259,8 @@ int dir_iterator_abort(struct dir_iterator *dir_iterator)
 			warning_errno("error closing directory '%s'",
 				      iter->base.path.buf);
 		}
+
+		string_list_clear(&level->entries, 0);
 	}
 
 	free(iter->levels);

dir-iterator.h

@@ -54,8 +54,11 @@
  *   and ITER_ERROR is returned immediately. In both cases, a meaningful
  *   warning is emitted. Note: ENOENT errors are always ignored so that
  *   the API users may remove files during iteration.
+ *
+ * - DIR_ITERATOR_SORTED: sort directory entries alphabetically.
  */
 #define DIR_ITERATOR_PEDANTIC (1 << 0)
+#define DIR_ITERATOR_SORTED   (1 << 1)
 
 struct dir_iterator {
 	/* The current path: */

refs.c

@@ -1594,10 +1594,6 @@ struct ref_iterator *refs_ref_iterator_begin(
 	if (trim)
 		iter = prefix_ref_iterator_begin(iter, "", trim);
 
-	/* Sanity check for subclasses: */
-	if (!iter->ordered)
-		BUG("reference iterator is not ordered");
-
 	return iter;
 }
 
@@ -2516,18 +2512,33 @@ cleanup:
 	return ret;
 }
 
-int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
+struct do_for_each_reflog_help {
+	each_reflog_fn *fn;
+	void *cb_data;
+};
+
+static int do_for_each_reflog_helper(struct repository *r UNUSED,
+				     const char *refname,
+				     const struct object_id *oid UNUSED,
+				     int flags,
+				     void *cb_data)
+{
+	struct do_for_each_reflog_help *hp = cb_data;
+	return hp->fn(refname, hp->cb_data);
+}
+
+int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data)
 {
 	struct ref_iterator *iter;
-	struct do_for_each_ref_help hp = { fn, cb_data };
+	struct do_for_each_reflog_help hp = { fn, cb_data };
 
 	iter = refs->be->reflog_iterator_begin(refs);
 
 	return do_for_each_repo_ref_iterator(the_repository, iter,
-					     do_for_each_ref_helper, &hp);
+					     do_for_each_reflog_helper, &hp);
 }
 
-int for_each_reflog(each_ref_fn fn, void *cb_data)
+int for_each_reflog(each_reflog_fn fn, void *cb_data)
 {
 	return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
 }

refs.h

@@ -534,12 +534,19 @@ int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_dat
 /* youngest entry first */
 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 
+/*
+ * The signature for the callback function for the {refs_,}for_each_reflog()
+ * functions below. The memory pointed to by the refname argument is only
+ * guaranteed to be valid for the duration of a single callback invocation.
+ */
+typedef int each_reflog_fn(const char *refname, void *cb_data);
+
 /*
  * Calls the specified function for each reflog file until it returns nonzero,
  * and returns the value. Reflog file order is unspecified.
  */
-int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
+int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data);
-int for_each_reflog(each_ref_fn fn, void *cb_data);
+int for_each_reflog(each_reflog_fn fn, void *cb_data);
 
 #define REFNAME_ALLOW_ONELEVEL 1
 #define REFNAME_REFSPEC_PATTERN 2

refs/debug.c

@@ -181,7 +181,6 @@ static int debug_ref_iterator_advance(struct ref_iterator *ref_iterator)
 		trace_printf_key(&trace_refs, "iterator_advance: %s (0)\n",
 			diter->iter->refname);
 
-	diter->base.ordered = diter->iter->ordered;
 	diter->base.refname = diter->iter->refname;
 	diter->base.oid = diter->iter->oid;
 	diter->base.flags = diter->iter->flags;
@@ -222,7 +221,7 @@ debug_ref_iterator_begin(struct ref_store *ref_store, const char *prefix,
 		drefs->refs->be->iterator_begin(drefs->refs, prefix,
 						exclude_patterns, flags);
 	struct debug_ref_iterator *diter = xcalloc(1, sizeof(*diter));
-	base_ref_iterator_init(&diter->base, &debug_ref_iterator_vtable, 1);
+	base_ref_iterator_init(&diter->base, &debug_ref_iterator_vtable);
 	diter->iter = res;
 	trace_printf_key(&trace_refs, "ref_iterator_begin: \"%s\" (0x%x)\n",
 			 prefix, flags);

refs/files-backend.c

@@ -879,8 +879,7 @@ static struct ref_iterator *files_ref_iterator_begin(
 
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
-	base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable,
+	base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
-			       overlay_iter->ordered);
 	iter->iter0 = overlay_iter;
 	iter->repo = ref_store->repo;
 	iter->flags = flags;
@@ -2116,10 +2115,8 @@ static int files_for_each_reflog_ent(struct ref_store *ref_store,
 
 struct files_reflog_iterator {
 	struct ref_iterator base;
-
 	struct ref_store *ref_store;
 	struct dir_iterator *dir_iterator;
-	struct object_id oid;
 };
 
 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
@@ -2130,25 +2127,13 @@ static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 	int ok;
 
 	while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
-		int flags;
-
 		if (!S_ISREG(diter->st.st_mode))
 			continue;
-		if (diter->basename[0] == '.')
+		if (check_refname_format(diter->basename,
+					 REFNAME_ALLOW_ONELEVEL))
 			continue;
-		if (ends_with(diter->basename, ".lock"))
-			continue;
-
-		if (!refs_resolve_ref_unsafe(iter->ref_store,
-					     diter->relative_path, 0,
-					     &iter->oid, &flags)) {
-			error("bad ref for %s", diter->path.buf);
-			continue;
-		}
 
 		iter->base.refname = diter->relative_path;
-		iter->base.oid = &iter->oid;
-		iter->base.flags = flags;
 		return ITER_OK;
 	}
 
@@ -2193,7 +2178,7 @@ static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
 
 	strbuf_addf(&sb, "%s/logs", gitdir);
 
-	diter = dir_iterator_begin(sb.buf, 0);
+	diter = dir_iterator_begin(sb.buf, DIR_ITERATOR_SORTED);
 	if (!diter) {
 		strbuf_release(&sb);
 		return empty_ref_iterator_begin();
@@ -2202,7 +2187,7 @@ static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
 
-	base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0);
+	base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
 	iter->dir_iterator = diter;
 	iter->ref_store = ref_store;
 	strbuf_release(&sb);
@@ -2210,32 +2195,6 @@ static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
 	return ref_iterator;
 }
 
-static enum iterator_selection reflog_iterator_select(
-	struct ref_iterator *iter_worktree,
-	struct ref_iterator *iter_common,
-	void *cb_data UNUSED)
-{
-	if (iter_worktree) {
-		/*
-		 * We're a bit loose here. We probably should ignore
-		 * common refs if they are accidentally added as
-		 * per-worktree refs.
-		 */
-		return ITER_SELECT_0;
-	} else if (iter_common) {
-		if (parse_worktree_ref(iter_common->refname, NULL, NULL,
-				       NULL) == REF_WORKTREE_SHARED)
-			return ITER_SELECT_1;
-
-		/*
-		 * The main ref store may contain main worktree's
-		 * per-worktree refs, which should be ignored
-		 */
-		return ITER_SKIP_1;
-	} else
-		return ITER_DONE;
-}
-
 static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
 {
 	struct files_ref_store *refs =
@@ -2246,9 +2205,9 @@ static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_st
 		return reflog_iterator_begin(ref_store, refs->gitcommondir);
 	} else {
 		return merge_ref_iterator_begin(
-			0, reflog_iterator_begin(ref_store, refs->base.gitdir),
+			reflog_iterator_begin(ref_store, refs->base.gitdir),
 			reflog_iterator_begin(ref_store, refs->gitcommondir),
-			reflog_iterator_select, refs);
+			ref_iterator_select, refs);
 	}
 }
 

refs/iterator.c

@@ -25,11 +25,9 @@ int ref_iterator_abort(struct ref_iterator *ref_iterator)
 }
 
 void base_ref_iterator_init(struct ref_iterator *iter,
-			    struct ref_iterator_vtable *vtable,
+			    struct ref_iterator_vtable *vtable)
-			    int ordered)
 {
 	iter->vtable = vtable;
-	iter->ordered = !!ordered;
 	iter->refname = NULL;
 	iter->oid = NULL;
 	iter->flags = 0;
@@ -74,7 +72,7 @@ struct ref_iterator *empty_ref_iterator_begin(void)
 	struct empty_ref_iterator *iter = xcalloc(1, sizeof(*iter));
 	struct ref_iterator *ref_iterator = &iter->base;
 
-	base_ref_iterator_init(ref_iterator, &empty_ref_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &empty_ref_iterator_vtable);
 	return ref_iterator;
 }
 
@@ -98,6 +96,49 @@ struct merge_ref_iterator {
 	struct ref_iterator **current;
 };
 
+enum iterator_selection ref_iterator_select(struct ref_iterator *iter_worktree,
+					    struct ref_iterator *iter_common,
+					    void *cb_data UNUSED)
+{
+	if (iter_worktree && !iter_common) {
+		/*
+		 * Return the worktree ref if there are no more common refs.
+		 */
+		return ITER_SELECT_0;
+	} else if (iter_common) {
+		/*
+		 * In case we have pending worktree and common refs we need to
+		 * yield them based on their lexicographical order. Worktree
+		 * refs that have the same name as common refs shadow the
+		 * latter.
+		 */
+		if (iter_worktree) {
+			int cmp = strcmp(iter_worktree->refname,
+					 iter_common->refname);
+			if (cmp < 0)
+				return ITER_SELECT_0;
+			else if (!cmp)
+				return ITER_SELECT_0_SKIP_1;
+		}
+
+		 /*
+		  * We now know that the lexicographically-next ref is a common
+		  * ref. When the common ref is a shared one we return it.
+		  */
+		if (parse_worktree_ref(iter_common->refname, NULL, NULL,
+				       NULL) == REF_WORKTREE_SHARED)
+			return ITER_SELECT_1;
+
+		/*
+		 * Otherwise, if the common ref is a per-worktree ref we skip
+		 * it because it would belong to the main worktree, not ours.
+		 */
+		return ITER_SKIP_1;
+	} else {
+		return ITER_DONE;
+	}
+}
+
 static int merge_ref_iterator_advance(struct ref_iterator *ref_iterator)
 {
 	struct merge_ref_iterator *iter =
@@ -207,7 +248,6 @@ static struct ref_iterator_vtable merge_ref_iterator_vtable = {
 };
 
 struct ref_iterator *merge_ref_iterator_begin(
-		int ordered,
 		struct ref_iterator *iter0, struct ref_iterator *iter1,
 		ref_iterator_select_fn *select, void *cb_data)
 {
@@ -222,7 +262,7 @@ struct ref_iterator *merge_ref_iterator_begin(
 	 * references through only if they exist in both iterators.
 	 */
 
-	base_ref_iterator_init(ref_iterator, &merge_ref_iterator_vtable, ordered);
+	base_ref_iterator_init(ref_iterator, &merge_ref_iterator_vtable);
 	iter->iter0 = iter0;
 	iter->iter1 = iter1;
 	iter->select = select;
@@ -271,12 +311,9 @@ struct ref_iterator *overlay_ref_iterator_begin(
 	} else if (is_empty_ref_iterator(back)) {
 		ref_iterator_abort(back);
 		return front;
-	} else if (!front->ordered || !back->ordered) {
-		BUG("overlay_ref_iterator requires ordered inputs");
 	}
 
-	return merge_ref_iterator_begin(1, front, back,
+	return merge_ref_iterator_begin(front, back, overlay_iterator_select, NULL);
-					overlay_iterator_select, NULL);
 }
 
 struct prefix_ref_iterator {
@@ -315,16 +352,12 @@ static int prefix_ref_iterator_advance(struct ref_iterator *ref_iterator)
 
 		if (cmp > 0) {
 			/*
-			 * If the source iterator is ordered, then we
+			 * As the source iterator is ordered, we
 			 * can stop the iteration as soon as we see a
 			 * refname that comes after the prefix:
 			 */
-			if (iter->iter0->ordered) {
 			ok = ref_iterator_abort(iter->iter0);
 			break;
-			} else {
-				continue;
-			}
 		}
 
 		if (iter->trim) {
@@ -396,7 +429,7 @@ struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
 
-	base_ref_iterator_init(ref_iterator, &prefix_ref_iterator_vtable, iter0->ordered);
+	base_ref_iterator_init(ref_iterator, &prefix_ref_iterator_vtable);
 
 	iter->iter0 = iter0;
 	iter->prefix = xstrdup(prefix);

refs/packed-backend.c

@@ -1111,7 +1111,7 @@ static struct ref_iterator *packed_ref_iterator_begin(
 
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
-	base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable);
 
 	if (exclude_patterns)
 		populate_excluded_jump_list(iter, snapshot, exclude_patterns);

refs/ref-cache.c

@@ -486,7 +486,7 @@ struct ref_iterator *cache_ref_iterator_begin(struct ref_cache *cache,
 
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
-	base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable);
 	ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
 
 	iter->levels_nr = 1;

refs/refs-internal.h

@@ -312,13 +312,6 @@ enum do_for_each_ref_flags {
  */
 struct ref_iterator {
 	struct ref_iterator_vtable *vtable;
-
-	/*
-	 * Does this `ref_iterator` iterate over references in order
-	 * by refname?
-	 */
-	unsigned int ordered : 1;
-
 	const char *refname;
 	const struct object_id *oid;
 	unsigned int flags;
@@ -386,15 +379,22 @@ typedef enum iterator_selection ref_iterator_select_fn(
 		struct ref_iterator *iter0, struct ref_iterator *iter1,
 		void *cb_data);
 
+/*
+ * An implementation of ref_iterator_select_fn that merges worktree and common
+ * refs. Per-worktree refs from the common iterator are ignored, worktree refs
+ * override common refs. Refs are selected lexicographically.
+ */
+enum iterator_selection ref_iterator_select(struct ref_iterator *iter_worktree,
+					    struct ref_iterator *iter_common,
+					    void *cb_data);
+
 /*
  * Iterate over the entries from iter0 and iter1, with the values
  * interleaved as directed by the select function. The iterator takes
  * ownership of iter0 and iter1 and frees them when the iteration is
- * over. A derived class should set `ordered` to 1 or 0 based on
+ * over.
- * whether it generates its output in order by reference name.
  */
 struct ref_iterator *merge_ref_iterator_begin(
-		int ordered,
 		struct ref_iterator *iter0, struct ref_iterator *iter1,
 		ref_iterator_select_fn *select, void *cb_data);
 
@@ -423,8 +423,6 @@ struct ref_iterator *overlay_ref_iterator_begin(
  * As an convenience to callers, if prefix is the empty string and
  * trim is zero, this function returns iter0 directly, without
  * wrapping it.
- *
- * The resulting ref_iterator is ordered if iter0 is.
  */
 struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 					       const char *prefix,
@@ -435,14 +433,11 @@ struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 /*
  * Base class constructor for ref_iterators. Initialize the
  * ref_iterator part of iter, setting its vtable pointer as specified.
- * `ordered` should be set to 1 if the iterator will iterate over
- * references in order by refname; otherwise it should be set to 0.
  * This is meant to be called only by the initializers of derived
  * classes.
  */
 void base_ref_iterator_init(struct ref_iterator *iter,
-			    struct ref_iterator_vtable *vtable,
+			    struct ref_iterator_vtable *vtable);
-			    int ordered);
 
 /*
  * Base class destructor for ref_iterators. Destroy the ref_iterator

refs/reftable-backend.c

@@ -479,7 +479,7 @@ static struct reftable_ref_iterator *ref_iterator_for_stack(struct reftable_ref_
 	int ret;
 
 	iter = xcalloc(1, sizeof(*iter));
-	base_ref_iterator_init(&iter->base, &reftable_ref_iterator_vtable, 1);
+	base_ref_iterator_init(&iter->base, &reftable_ref_iterator_vtable);
 	iter->prefix = prefix;
 	iter->base.oid = &iter->oid;
 	iter->flags = flags;
@@ -504,49 +504,6 @@ done:
 	return iter;
 }
 
-static enum iterator_selection iterator_select(struct ref_iterator *iter_worktree,
-					       struct ref_iterator *iter_common,
-					       void *cb_data UNUSED)
-{
-	if (iter_worktree && !iter_common) {
-		/*
-		 * Return the worktree ref if there are no more common refs.
-		 */
-		return ITER_SELECT_0;
-	} else if (iter_common) {
-		/*
-		 * In case we have pending worktree and common refs we need to
-		 * yield them based on their lexicographical order. Worktree
-		 * refs that have the same name as common refs shadow the
-		 * latter.
-		 */
-		if (iter_worktree) {
-			int cmp = strcmp(iter_worktree->refname,
-					 iter_common->refname);
-			if (cmp < 0)
-				return ITER_SELECT_0;
-			else if (!cmp)
-				return ITER_SELECT_0_SKIP_1;
-		}
-
-		 /*
-		  * We now know that the lexicographically-next ref is a common
-		  * ref. When the common ref is a shared one we return it.
-		  */
-		if (parse_worktree_ref(iter_common->refname, NULL, NULL,
-				       NULL) == REF_WORKTREE_SHARED)
-			return ITER_SELECT_1;
-
-		/*
-		 * Otherwise, if the common ref is a per-worktree ref we skip
-		 * it because it would belong to the main worktree, not ours.
-		 */
-		return ITER_SKIP_1;
-	} else {
-		return ITER_DONE;
-	}
-}
-
 static struct ref_iterator *reftable_be_iterator_begin(struct ref_store *ref_store,
 						       const char *prefix,
 						       const char **exclude_patterns,
@@ -575,8 +532,8 @@ static struct ref_iterator *reftable_be_iterator_begin(struct ref_store *ref_sto
 	 * single iterator.
 	 */
 	worktree_iter = ref_iterator_for_stack(refs, refs->worktree_stack, prefix, flags);
-	return merge_ref_iterator_begin(1, &worktree_iter->base, &main_iter->base,
+	return merge_ref_iterator_begin(&worktree_iter->base, &main_iter->base,
-					iterator_select, NULL);
+					ref_iterator_select, NULL);
 }
 
 static int reftable_be_read_raw_ref(struct ref_store *ref_store,
@@ -1637,7 +1594,6 @@ struct reftable_reflog_iterator {
 	struct reftable_ref_store *refs;
 	struct reftable_iterator iter;
 	struct reftable_log_record log;
-	struct object_id oid;
 	char *last_name;
 	int err;
 };
@@ -1648,8 +1604,6 @@ static int reftable_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 		(struct reftable_reflog_iterator *)ref_iterator;
 
 	while (!iter->err) {
-		int flags;
-
 		iter->err = reftable_iterator_next_log(&iter->iter, &iter->log);
 		if (iter->err)
 			break;
@@ -1662,17 +1616,13 @@ static int reftable_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 		if (iter->last_name && !strcmp(iter->log.refname, iter->last_name))
 			continue;
 
-		if (!refs_resolve_ref_unsafe(&iter->refs->base, iter->log.refname,
+		if (check_refname_format(iter->log.refname,
-					     0, &iter->oid, &flags)) {
+					 REFNAME_ALLOW_ONELEVEL))
-			error(_("bad ref for %s"), iter->log.refname);
 			continue;
-		}
 
 		free(iter->last_name);
 		iter->last_name = xstrdup(iter->log.refname);
 		iter->base.refname = iter->log.refname;
-		iter->base.oid = &iter->oid;
-		iter->base.flags = flags;
 
 		break;
 	}
@@ -1723,9 +1673,8 @@ static struct reftable_reflog_iterator *reflog_iterator_for_stack(struct reftabl
 	int ret;
 
 	iter = xcalloc(1, sizeof(*iter));
-	base_ref_iterator_init(&iter->base, &reftable_reflog_iterator_vtable, 1);
+	base_ref_iterator_init(&iter->base, &reftable_reflog_iterator_vtable);
 	iter->refs = refs;
-	iter->base.oid = &iter->oid;
 
 	ret = refs->err;
 	if (ret)
@@ -1758,8 +1707,8 @@ static struct ref_iterator *reftable_be_reflog_iterator_begin(struct ref_store *
 
 	worktree_iter = reflog_iterator_for_stack(refs, refs->worktree_stack);
 
-	return merge_ref_iterator_begin(1, &worktree_iter->base, &main_iter->base,
+	return merge_ref_iterator_begin(&worktree_iter->base, &main_iter->base,
-					iterator_select, NULL);
+					ref_iterator_select, NULL);
 }
 
 static int yield_log_record(struct reftable_log_record *log,

revision.c

@@ -1686,9 +1686,7 @@ static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 	return 0;
 }
 
-static int handle_one_reflog(const char *refname_in_wt,
+static int handle_one_reflog(const char *refname_in_wt, void *cb_data)
-			     const struct object_id *oid UNUSED,
-			     int flag UNUSED, void *cb_data)
 {
 	struct all_refs_cb *cb = cb_data;
 	struct strbuf refname = STRBUF_INIT;

t/helper/test-ref-store.c

@@ -221,13 +221,19 @@ static int cmd_verify_ref(struct ref_store *refs, const char **argv)
 	return ret;
 }
 
+static int each_reflog(const char *refname, void *cb_data UNUSED)
+{
+	printf("%s\n", refname);
+	return 0;
+}
+
 static int cmd_for_each_reflog(struct ref_store *refs,
 			       const char **argv UNUSED)
 {
-	return refs_for_each_reflog(refs, each_ref, NULL);
+	return refs_for_each_reflog(refs, each_reflog, NULL);
 }
 
-static int each_reflog(struct object_id *old_oid, struct object_id *new_oid,
+static int each_reflog_ent(struct object_id *old_oid, struct object_id *new_oid,
 			   const char *committer, timestamp_t timestamp,
 			   int tz, const char *msg, void *cb_data UNUSED)
 {
@@ -241,14 +247,14 @@ static int cmd_for_each_reflog_ent(struct ref_store *refs, const char **argv)
 {
 	const char *refname = notnull(*argv++, "refname");
 
-	return refs_for_each_reflog_ent(refs, refname, each_reflog, refs);
+	return refs_for_each_reflog_ent(refs, refname, each_reflog_ent, refs);
 }
 
 static int cmd_for_each_reflog_ent_reverse(struct ref_store *refs, const char **argv)
 {
 	const char *refname = notnull(*argv++, "refname");
 
-	return refs_for_each_reflog_ent_reverse(refs, refname, each_reflog, refs);
+	return refs_for_each_reflog_ent_reverse(refs, refname, each_reflog_ent, refs);
 }
 
 static int cmd_reflog_exists(struct ref_store *refs, const char **argv)

t/t0600-reffiles-backend.sh

@@ -287,23 +287,23 @@ test_expect_success 'for_each_reflog()' '
 	mkdir -p     .git/worktrees/wt/logs/refs/bisect &&
 	echo $ZERO_OID > .git/worktrees/wt/logs/refs/bisect/wt-random &&
 
-	$RWT for-each-reflog | cut -d" " -f 2- | sort >actual &&
+	$RWT for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
+	HEAD
-	PSEUDO-WT 0x0
+	PSEUDO-WT
-	refs/bisect/wt-random 0x0
+	refs/bisect/wt-random
-	refs/heads/main 0x0
+	refs/heads/main
-	refs/heads/wt-main 0x0
+	refs/heads/wt-main
 	EOF
 	test_cmp expected actual &&
 
-	$RMAIN for-each-reflog | cut -d" " -f 2- | sort >actual &&
+	$RMAIN for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
+	HEAD
-	PSEUDO-MAIN 0x0
+	PSEUDO-MAIN
-	refs/bisect/random 0x0
+	refs/bisect/random
-	refs/heads/main 0x0
+	refs/heads/main
-	refs/heads/wt-main 0x0
+	refs/heads/wt-main
 	EOF
 	test_cmp expected actual
 '

t/t1405-main-ref-store.sh

@@ -68,11 +68,11 @@ test_expect_success 'verify_ref(new-main)' '
 '
 
 test_expect_success 'for_each_reflog()' '
-	$RUN for-each-reflog | sort -k2 | cut -d" " -f 2- >actual &&
+	$RUN for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
+	HEAD
-	refs/heads/main 0x0
+	refs/heads/main
-	refs/heads/new-main 0x0
+	refs/heads/new-main
 	EOF
 	test_cmp expected actual
 '

t/t1406-submodule-ref-store.sh

@@ -63,11 +63,11 @@ test_expect_success 'verify_ref(new-main)' '
 '
 
 test_expect_success 'for_each_reflog()' '
-	$RUN for-each-reflog | sort | cut -d" " -f 2- >actual &&
+	$RUN for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
+	HEAD
-	refs/heads/main 0x0
+	refs/heads/main
-	refs/heads/new-main 0x0
+	refs/heads/new-main
 	EOF
 	test_cmp expected actual
 '

t/t1410-reflog.sh

@@ -436,4 +436,112 @@ test_expect_success 'empty reflog' '
 	test_must_be_empty err
 '
 
+test_expect_success 'list reflogs' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git reflog list >actual &&
+		test_must_be_empty actual &&
+
+		test_commit A &&
+		cat >expect <<-EOF &&
+		HEAD
+		refs/heads/main
+		EOF
+		git reflog list >actual &&
+		test_cmp expect actual &&
+
+		git branch b &&
+		cat >expect <<-EOF &&
+		HEAD
+		refs/heads/b
+		refs/heads/main
+		EOF
+		git reflog list >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'list reflogs with worktree' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+
+		test_commit A &&
+		git worktree add wt &&
+		git -c core.logAllRefUpdates=always \
+			update-ref refs/worktree/main HEAD &&
+		git -c core.logAllRefUpdates=always \
+			update-ref refs/worktree/per-worktree HEAD &&
+		git -c core.logAllRefUpdates=always -C wt \
+			update-ref refs/worktree/per-worktree HEAD &&
+		git -c core.logAllRefUpdates=always -C wt \
+			update-ref refs/worktree/worktree HEAD &&
+
+		cat >expect <<-EOF &&
+		HEAD
+		refs/heads/main
+		refs/heads/wt
+		refs/worktree/main
+		refs/worktree/per-worktree
+		EOF
+		git reflog list >actual &&
+		test_cmp expect actual &&
+
+		cat >expect <<-EOF &&
+		HEAD
+		refs/heads/main
+		refs/heads/wt
+		refs/worktree/per-worktree
+		refs/worktree/worktree
+		EOF
+		git -C wt reflog list >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'reflog list returns error with additional args' '
+	cat >expect <<-EOF &&
+	error: list does not accept arguments: ${SQ}bogus${SQ}
+	EOF
+	test_must_fail git reflog list bogus 2>err &&
+	test_cmp expect err
+'
+
+test_expect_success 'reflog for symref with unborn target can be listed' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit A &&
+		git symbolic-ref HEAD refs/heads/unborn &&
+		cat >expect <<-EOF &&
+		HEAD
+		refs/heads/main
+		EOF
+		git reflog list >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'reflog with invalid object ID can be listed' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit A &&
+		test-tool ref-store main update-ref msg refs/heads/missing \
+			$(test_oid deadbeef) "$ZERO_OID" REF_SKIP_OID_VERIFICATION &&
+		cat >expect <<-EOF &&
+		HEAD
+		refs/heads/main
+		refs/heads/missing
+		EOF
+		git reflog list >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_done