fix: anomynous users code search for private/limited user's repository

- Consider private/limited users in the `AccessibleRepositoryCondition`
query, previously this only considered private/limited organization.
This limits the ability for anomynous users to do code search on
private/limited user's repository
- Unit test added.

(cherry picked from commit b70196653f)

models/repo/TestSearchRepositoryIDsByCondition/repository.yml

@@ -0,0 +1,30 @@
+-
+  id: 1001
+  owner_id: 33
+  owner_name: user33
+  lower_name: repo1001
+  name: repo1001
+  default_branch: main
+  num_watches: 0
+  num_stars: 0
+  num_forks: 0
+  num_issues: 0
+  num_closed_issues: 0
+  num_pulls: 0
+  num_closed_pulls: 0
+  num_milestones: 0
+  num_closed_milestones: 0
+  num_projects: 0
+  num_closed_projects: 0
+  is_private: false
+  is_empty: false
+  is_archived: false
+  is_mirror: false
+  status: 0
+  is_fork: false
+  fork_id: 0
+  is_template: false
+  template_id: 0
+  size: 0
+  is_fsck_enabled: true
+  close_issues_via_commit_in_any_branch: false

models/repo/repo_list.go

@@ -665,12 +665,9 @@ func AccessibleRepositoryCondition(user *user_model.User, unitType unit.Type) bu
 		// 1. Be able to see all non-private repositories that either:
 		cond = cond.Or(builder.And(
 			builder.Eq{"`repository`.is_private": false},
-			// 2. Aren't in an private organisation or limited organisation if we're not logged in
+			// 2. Aren't in an private organisation/user or limited organisation/user if the doer is not logged in.
 			builder.NotIn("`repository`.owner_id", builder.Select("id").From("`user`").Where(
-				builder.And(
+				builder.In("visibility", orgVisibilityLimit)))))
-					builder.Eq{"type": user_model.UserTypeOrganization},
-					builder.In("visibility", orgVisibilityLimit)),
-			))))
 	}
 
 	if user != nil {

models/repo/repo_list_test.go

@@ -4,13 +4,18 @@
 package repo_test
 
 import (
+	"path/filepath"
+	"slices"
 	"strings"
 	"testing"
 
 	"code.gitea.io/gitea/models/db"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/optional"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -403,3 +408,43 @@ func TestSearchRepositoryByTopicName(t *testing.T) {
 		})
 	}
 }
+
+func TestSearchRepositoryIDsByCondition(t *testing.T) {
+	defer unittest.OverrideFixtures(
+		unittest.FixturesOptions{
+			Dir:  filepath.Join(setting.AppWorkPath, "models/fixtures/"),
+			Base: setting.AppWorkPath,
+			Dirs: []string{"models/repo/TestSearchRepositoryIDsByCondition/"},
+		},
+	)()
+	require.NoError(t, unittest.PrepareTestDatabase())
+	// Sanity check of the database
+	limitedUser := unittest.AssertExistsAndLoadBean(t, &user.User{ID: 33, Visibility: structs.VisibleTypeLimited})
+	unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1001, OwnerID: limitedUser.ID})
+
+	testCases := []struct {
+		user    *user.User
+		repoIDs []int64
+	}{
+		{
+			user:    nil,
+			repoIDs: []int64{1, 4, 8, 9, 10, 11, 12, 14, 17, 18, 21, 23, 25, 27, 29, 32, 33, 34, 35, 36, 37, 42, 44, 45, 46, 47, 48, 49, 50, 51, 53, 57, 58, 60, 61, 1059},
+		},
+		{
+			user:    unittest.AssertExistsAndLoadBean(t, &user.User{ID: 4}),
+			repoIDs: []int64{1, 3, 4, 8, 9, 10, 11, 12, 14, 17, 18, 21, 23, 25, 27, 29, 32, 33, 34, 35, 36, 37, 38, 40, 42, 44, 45, 46, 47, 48, 49, 50, 51, 53, 57, 58, 60, 61, 1001, 1059},
+		},
+		{
+			user:    unittest.AssertExistsAndLoadBean(t, &user.User{ID: 5}),
+			repoIDs: []int64{1, 4, 8, 9, 10, 11, 12, 14, 17, 18, 21, 23, 25, 27, 29, 32, 33, 34, 35, 36, 37, 38, 40, 42, 44, 45, 46, 47, 48, 49, 50, 51, 53, 57, 58, 60, 61, 1001, 1059},
+		},
+	}
+
+	for _, testCase := range testCases {
+		repoIDs, err := repo_model.FindUserCodeAccessibleRepoIDs(db.DefaultContext, testCase.user)
+		require.NoError(t, err)
+
+		slices.Sort(repoIDs)
+		assert.EqualValues(t, testCase.repoIDs, repoIDs)
+	}
+}