allow action user have read permission in public repo like other user

models/perm/access/repo_permission.go

@@ -276,8 +276,14 @@ func GetActionsUserRepoPermission(ctx context.Context, repo *repo_model.Reposito
 		if !actionsCfg.IsCollaborativeOwner(taskRepo.OwnerID) || !taskRepo.IsPrivate {
 			// The task repo can access the current repo only if the task repo is private and
 			// the owner of the task repo is a collaborative owner of the current repo.
-			// FIXME allow public repo read access if tokenless pull is enabled
 			// FIXME should owner's visibility also be considered here?
+
+			// check permission like simple user but limit to read-only
+			perm, err = GetUserRepoPermission(ctx, repo, user_model.NewActionsUser())
+			if err != nil {
+				return perm, err
+			}
+			perm.AccessMode = min(perm.AccessMode, perm_model.AccessModeRead)
 			return perm, nil
 		}
 		accessMode = perm_model.AccessModeRead

tests/integration/api_actions_permission_test.go

@@ -0,0 +1,52 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"net/http"
+	"testing"
+
+	"code.gitea.io/gitea/modules/setting"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/test"
+	"code.gitea.io/gitea/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestActionUserSignIn(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	req := NewRequest(t, "GET", "/api/v1/user").
+		AddTokenAuth("8061e833a55f6fc0157c98b883e91fcfeeb1a71a")
+	resp := MakeRequest(t, req, http.StatusOK)
+
+	var u api.User
+	DecodeJSON(t, resp, &u)
+	assert.Equal(t, "gitea-actions", u.UserName)
+}
+
+func TestActionUserAccessPublicRepo(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	req := NewRequestf(t, "GET", "/api/v1/repos/user2/repo1/raw/README.md").
+		AddTokenAuth("8061e833a55f6fc0157c98b883e91fcfeeb1a71a")
+	resp := MakeRequest(t, req, http.StatusOK)
+	assert.Equal(t, "file", resp.Header().Get("x-gitea-object-type"))
+
+	defer test.MockVariableValue(&setting.Service.RequireSignInViewStrict, true)()
+
+	req = NewRequestf(t, "GET", "/api/v1/repos/user2/repo1/raw/README.md").
+		AddTokenAuth("8061e833a55f6fc0157c98b883e91fcfeeb1a71a")
+	resp = MakeRequest(t, req, http.StatusOK)
+	assert.Equal(t, "file", resp.Header().Get("x-gitea-object-type"))
+}
+
+func TestActionUserNoAccessOtherPrivateRepo(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	req := NewRequestf(t, "GET", "/api/v1/repos/user2/repo2/raw/README.md").
+		AddTokenAuth("8061e833a55f6fc0157c98b883e91fcfeeb1a71a")
+	MakeRequest(t, req, http.StatusNotFound)
+}