@@ -402,8 +402,10 @@ will be automatically changed to version `1`.
 	of filenames that cause collisions in Git's default name-hash
 	algorithm.
 +
-Incompatible with `--delta-islands`. The `--use-bitmap-index` option is
-ignored in the presence of `--path-walk`. The `--path-walk` option
+Incompatible with `--delta-islands`. When `--use-bitmap-index` is
+specified with `--path-walk`, a successful bitmap traversal is used for
+object enumeration, with path-walk remaining as the fallback traversal
+when the bitmap cannot satisfy the request. The `--path-walk` option
 supports the `--filter=<spec>` forms `blob:none`, `blob:limit=<n>`,
 `tree:0`, `object:type=<type>`, and `sparse:<oid>`. These supported filter
 types can be combined with the `combine:<spec>+<spec>` form.
 
@@ -4742,6 +4742,15 @@ static int add_objects_by_path(const char *path,
 			continue;
 
 		add_object_entry(oid, type, path, exclude);
+
+		if (type == OBJ_COMMIT && write_bitmap_index) {
+			struct commit *commit;
+
+			commit = lookup_commit(the_repository, oid);
+			if (!commit)
+				die(_("could not find commit %s"), oid_to_hex(oid));
+			index_commit_for_bitmap(commit);
+		}
 	}
 
 	oe_end = to_pack.nr_objects;
@@ -4774,6 +4783,13 @@ static int get_object_list_path_walk(struct rev_info *revs)
 	info.path_fn = add_objects_by_path;
 	info.path_fn_data = &processed;
 
+	/*
+	 * Path-walk needs boundary commits to discover thin-pack bases, but
+	 * bitmap traversal does not understand the boundary state. Set it
+	 * here so any prior bitmap attempt sees the usual non-boundary walk.
+	 */
+	revs->boundary = 1;
+
 	/*
 	 * Allow the --[no-]sparse option to be interesting here, if only
 	 * for testing purposes. Paths with no interesting objects will not
@@ -5205,9 +5221,7 @@ int cmd_pack_objects(int argc,
 		}
 	}
 	if (path_walk) {
-		strvec_push(&rp, "--boundary");
 		strvec_push(&rp, "--objects");
-		use_bitmap_index = 0;
 	} else if (thin) {
 		use_internal_rev_list = 1;
 		strvec_push(&rp, shallow
 
@@ -4,23 +4,30 @@ test_description='performance of fetches from bitmapped packs'
 . ./perf-lib.sh
 
 test_fetch_bitmaps () {
+	argv=$1
+	export argv
+
 	test_expect_success 'setup test directory' '
 		rm -fr * .git
 	'
 
 	test_perf_default_repo
 
-	test_expect_success 'create bitmapped server repo' '
+	test_expect_success "create bitmapped server repo ${argv:+($argv)}" '
 		git config pack.writebitmaps true &&
-		git repack -ad
+		git repack -adF $argv
+	'
+
+	test_size "size of bitmapped pack ${argv:+($argv)}" '
+		test_file_size .git/objects/pack/pack-*.pack
 	'
 
 	# simulate a fetch from a repository that last fetched N days ago, for
 	# various values of N. We do so by following the first-parent chain,
 	# and assume the first entry in the chain that is N days older than the current
 	# HEAD is where the HEAD would have been then.
 	for days in 1 2 4 8 16 32 64 128; do
-		title=$(printf '%10s' "($days days)")
+		title=$(printf '%10s' "($days days${argv:+, $argv})")
 		test_expect_success "setup revs from $days days ago" '
 			now=$(git log -1 --format=%ct HEAD) &&
 			then=$(($now - ($days * 86400))) &&
@@ -47,6 +54,9 @@ test_fetch_bitmaps () {
 	done
 }
 
-test_fetch_bitmaps
+for argv in '' --path-walk
+do
+	test_fetch_bitmaps $argv || return 1
+done
 
 test_done
@@ -577,6 +577,42 @@ test_bitmap_cases
 
 sane_unset GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL
 
+test_expect_success 'path-walk repack can write and use bitmap indexes' '
+	test_when_finished "rm -rf path-walk-bitmap" &&
+	git init path-walk-bitmap &&
+	(
+		cd path-walk-bitmap &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+
+		git repack -a -d -b --path-walk &&
+		git rev-list --test-bitmap --use-bitmap-index HEAD &&
+
+		git rev-parse HEAD >in &&
+
+		git rev-list --objects --no-object-names HEAD >expect.raw &&
+		sort expect.raw >expect &&
+
+		for reuse in true false
+		do
+			: >trace.txt &&
+
+			GIT_TRACE2_EVENT="$(pwd)/trace.txt" \
+			git -c pack.allowPackReuse=$reuse pack-objects \
+				--stdout --revs --path-walk --use-bitmap-index \
+				<in >out.pack &&
+			test_grep "\"category\":\"bitmap\",\"key\":\"bitmap/hits\"" trace.txt &&
+
+			git index-pack out.pack &&
+
+			list_packed_objects out.idx >actual.raw &&
+			sort actual.raw >actual &&
+			test_cmp expect actual || return 1
+		done
+	)
+'
+
 test_expect_success 'incremental repack fails when bitmaps are requested' '
 	test_commit more-1 &&
 	test_must_fail git repack -d 2>err &&