Merge branch 'cc/rev-list-allow-missing-tips'

"git rev-list --missing=print" has learned to optionally take
"--allow-missing-tips", which allows the objects at the starting
points to be missing.

* cc/rev-list-allow-missing-tips:
  revision: fix --missing=[print|allow*] for annotated tags
  rev-list: allow missing tips with --missing=[print|allow*]
  t6022: fix 'test' style and 'even though' typo
  oidset: refactor oidset_insert_from_set()
  revision: clarify a 'return NULL' in get_reference()

Documentation/rev-list-options.txt

@@ -1019,6 +1019,10 @@ Unexpected missing objects will raise an error.
 +
 The form '--missing=print' is like 'allow-any', but will also print a
 list of the missing objects.  Object IDs are prefixed with a ``?'' character.
++
+If some tips passed to the traversal are missing, they will be
+considered as missing too, and the traversal will ignore them. In case
+we cannot get their Object ID though, an error will be raised.
 
 --exclude-promisor-objects::
 	(For internal use only.)  Prefilter object traversal at

builtin/rev-list.c

@@ -545,6 +545,18 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	 *
 	 * Let "--missing" to conditionally set fetch_if_missing.
 	 */
+	/*
+	 * NEEDSWORK: These loops that attempt to find presence of
+	 * options without understanding that the options they are
+	 * skipping are broken (e.g., it would not know "--grep
+	 * --exclude-promisor-objects" is not triggering
+	 * "--exclude-promisor-objects" option).  We really need
+	 * setup_revisions() to have a mechanism to allow and disallow
+	 * some sets of options for different commands (like rev-list,
+	 * replay, etc). Such a mechanism should do an early parsing
+	 * of options and be able to manage the `--missing=...` and
+	 * `--exclude-promisor-objects` options below.
+	 */
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 		if (!strcmp(arg, "--exclude-promisor-objects")) {
@@ -753,8 +765,12 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 
 	if (arg_print_omitted)
 		oidset_init(&omitted_objects, DEFAULT_OIDSET_SIZE);
-	if (arg_missing_action == MA_PRINT)
+	if (arg_missing_action == MA_PRINT) {
 		oidset_init(&missing_objects, DEFAULT_OIDSET_SIZE);
+		/* Add missing tips */
+		oidset_insert_from_set(&missing_objects, &revs.missing_commits);
+		oidset_clear(&revs.missing_commits);
+	}
 
 	traverse_commit_list_filtered(
 		&revs, show_commit, show_object, &info,

list-objects-filter.c

@@ -711,15 +711,6 @@ static void filter_combine__free(void *filter_data)
 	free(d);
 }
 
-static void add_all(struct oidset *dest, struct oidset *src) {
-	struct oidset_iter iter;
-	struct object_id *src_oid;
-
-	oidset_iter_init(src, &iter);
-	while ((src_oid = oidset_iter_next(&iter)) != NULL)
-		oidset_insert(dest, src_oid);
-}
-
 static void filter_combine__finalize_omits(
 	struct oidset *omits,
 	void *filter_data)
@@ -728,7 +719,7 @@ static void filter_combine__finalize_omits(
 	size_t sub;
 
 	for (sub = 0; sub < d->nr; sub++) {
-		add_all(omits, &d->sub[sub].omits);
+		oidset_insert_from_set(omits, &d->sub[sub].omits);
 		oidset_clear(&d->sub[sub].omits);
 	}
 }

oidset.c

@@ -23,6 +23,16 @@ int oidset_insert(struct oidset *set, const struct object_id *oid)
 	return !added;
 }
 
+void oidset_insert_from_set(struct oidset *dest, struct oidset *src)
+{
+	struct oidset_iter iter;
+	struct object_id *src_oid;
+
+	oidset_iter_init(src, &iter);
+	while ((src_oid = oidset_iter_next(&iter)))
+		oidset_insert(dest, src_oid);
+}
+
 int oidset_remove(struct oidset *set, const struct object_id *oid)
 {
 	khiter_t pos = kh_get_oid_set(&set->set, *oid);

oidset.h

@@ -47,6 +47,12 @@ int oidset_contains(const struct oidset *set, const struct object_id *oid);
  */
 int oidset_insert(struct oidset *set, const struct object_id *oid);
 
+/**
+ * Insert all the oids that are in set 'src' into set 'dest'; a copy
+ * is made of each oid inserted into set 'dest'.
+ */
+void oidset_insert_from_set(struct oidset *dest, struct oidset *src);
+
 /**
  * Remove the oid from the set.
  *

revision.c

@@ -385,9 +385,13 @@ static struct object *get_reference(struct rev_info *revs, const char *name,
 
 	if (!object) {
 		if (revs->ignore_missing)
-			return object;
+			return NULL;
 		if (revs->exclude_promisor_objects && is_promisor_object(oid))
 			return NULL;
+		if (revs->do_not_die_on_missing_objects) {
+			oidset_insert(&revs->missing_commits, oid);
+			return NULL;
+		}
 		die("bad object %s", name);
 	}
 	object->flags |= flags;
@@ -415,15 +419,21 @@ static struct commit *handle_commit(struct rev_info *revs,
 	 */
 	while (object->type == OBJ_TAG) {
 		struct tag *tag = (struct tag *) object;
+		struct object_id *oid;
 		if (revs->tag_objects && !(flags & UNINTERESTING))
 			add_pending_object(revs, object, tag->tag);
-		object = parse_object(revs->repo, get_tagged_oid(tag));
+		oid = get_tagged_oid(tag);
+		object = parse_object(revs->repo, oid);
 		if (!object) {
 			if (revs->ignore_missing_links || (flags & UNINTERESTING))
 				return NULL;
 			if (revs->exclude_promisor_objects &&
 			    is_promisor_object(&tag->tagged->oid))
 				return NULL;
+			if (revs->do_not_die_on_missing_objects && oid) {
+				oidset_insert(&revs->missing_commits, oid);
+				return NULL;
+			}
 			die("bad object %s", oid_to_hex(&tag->tagged->oid));
 		}
 		object->flags |= flags;
@@ -1945,6 +1955,7 @@ void repo_init_revisions(struct repository *r,
 	init_display_notes(&revs->notes_opt);
 	list_objects_filter_init(&revs->filter);
 	init_ref_exclusions(&revs->ref_excludes);
+	oidset_init(&revs->missing_commits, 0);
 }
 
 static void add_pending_commit_list(struct rev_info *revs,
@@ -2176,13 +2187,18 @@ static int handle_revision_arg_1(const char *arg_, struct rev_info *revs, int fl
 	if (revarg_opt & REVARG_COMMITTISH)
 		get_sha1_flags |= GET_OID_COMMITTISH;
 
+	/*
+	 * Even if revs->do_not_die_on_missing_objects is set, we
+	 * should error out if we can't even get an oid, as
+	 * `--missing=print` should be able to report missing oids.
+	 */
 	if (get_oid_with_context(revs->repo, arg, get_sha1_flags, &oid, &oc))
 		return revs->ignore_missing ? 0 : -1;
 	if (!cant_be_filename)
 		verify_non_filename(revs->prefix, arg);
 	object = get_reference(revs, arg, &oid, flags ^ local_flags);
 	if (!object)
-		return revs->ignore_missing ? 0 : -1;
+		return (revs->ignore_missing || revs->do_not_die_on_missing_objects) ? 0 : -1;
 	add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
 	add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
 	free(oc.path);
@@ -3828,8 +3844,6 @@ int prepare_revision_walk(struct rev_info *revs)
 				       FOR_EACH_OBJECT_PROMISOR_ONLY);
 	}
 
-	oidset_init(&revs->missing_commits, 0);
-
 	if (!revs->reflog_info)
 		prepare_to_use_bloom_filter(revs);
 	if (!revs->unsorted_input)

t/t6022-rev-list-missing.sh

@@ -10,7 +10,10 @@ TEST_PASSES_SANITIZE_LEAK=true
 test_expect_success 'create repository and alternate directory' '
 	test_commit 1 &&
 	test_commit 2 &&
-	test_commit 3
+	test_commit 3 &&
+	git tag -m "tag message" annot_tag HEAD~1 &&
+	git tag regul_tag HEAD~1 &&
+	git branch a_branch HEAD~1
 '
 
 # We manually corrupt the repository, which means that the commit-graph may
@@ -46,9 +49,10 @@ do
 			git rev-list --objects --no-object-names \
 				HEAD ^$obj >expect.raw &&
 
-			# Blobs are shared by all commits, so evethough a commit/tree
+			# Blobs are shared by all commits, so even though a commit/tree
 			# might be skipped, its blob must be accounted for.
-			if [ $obj != "HEAD:1.t" ]; then
+			if test $obj != "HEAD:1.t"
+			then
 				echo $(git rev-parse HEAD:1.t) >>expect.raw &&
 				echo $(git rev-parse HEAD:2.t) >>expect.raw
 			fi &&
@@ -77,4 +81,69 @@ do
 	done
 done
 
+for missing_tip in "annot_tag" "regul_tag" "a_branch" "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
+do
+	# We want to check that things work when both
+	#   - all the tips passed are missing (case existing_tip = ""), and
+	#   - there is one missing tip and one existing tip (case existing_tip = "HEAD")
+	for existing_tip in "" "HEAD"
+	do
+		for action in "allow-any" "print"
+		do
+			test_expect_success "--missing=$action with tip '$missing_tip' missing and tip '$existing_tip'" '
+				# Before the object is made missing, we use rev-list to
+				# get the expected oids.
+				if test "$existing_tip" = "HEAD"
+				then
+					git rev-list --objects --no-object-names \
+						HEAD ^$missing_tip >expect.raw
+				else
+					>expect.raw
+				fi &&
+
+				# Blobs are shared by all commits, so even though a commit/tree
+				# might be skipped, its blob must be accounted for.
+				if test "$existing_tip" = "HEAD" && test $missing_tip != "HEAD:1.t"
+				then
+					echo $(git rev-parse HEAD:1.t) >>expect.raw &&
+					echo $(git rev-parse HEAD:2.t) >>expect.raw
+				fi &&
+
+				missing_oid="$(git rev-parse $missing_tip)" &&
+
+				if test "$missing_tip" = "annot_tag"
+				then
+					oid="$(git rev-parse $missing_tip^{commit})" &&
+					echo "$missing_oid" >>expect.raw
+				else
+					oid="$missing_oid"
+				fi &&
+
+				path=".git/objects/$(test_oid_to_path $oid)" &&
+
+				mv "$path" "$path.hidden" &&
+				test_when_finished "mv $path.hidden $path" &&
+
+				git rev-list --missing=$action --objects --no-object-names \
+				     $missing_oid $existing_tip >actual.raw &&
+
+				# When the action is to print, we should also add the missing
+				# oid to the expect list.
+				case $action in
+				allow-any)
+					;;
+				print)
+					grep ?$oid actual.raw &&
+					echo ?$oid >>expect.raw
+					;;
+				esac &&
+
+				sort actual.raw >actual &&
+				sort expect.raw >expect &&
+				test_cmp expect actual
+			'
+		done
+	done
+done
+
 test_done