Optionally allow anyone to edit Wikis

This is largely based on gitea#6312 by @ashimokawa, with updates and
fixes by myself, and incorporates the review feedback given in that pull
request, and more.

What this patch does is add a new "default_permissions" column to the
`repo_units` table (defaulting to read permission), adjusts the
permission checking code to take this into consideration, and then
exposes a setting that lets a repo administrator enable any user on a
Forgejo instance to edit the repo's wiki (effectively giving the wiki
unit of the repo "write" permissions by default).

By default, wikis will remain restricted to collaborators, but with the
new setting exposed, they can be turned into globally editable wikis.

Fixes Codeberg/Community#28.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>

models/forgejo_migrations/migrate.go

@@ -10,6 +10,7 @@ import (
 
 	"code.gitea.io/gitea/models/forgejo/semver"
 	forgejo_v1_20 "code.gitea.io/gitea/models/forgejo_migrations/v1_20"
+	forgejo_v1_22 "code.gitea.io/gitea/models/forgejo_migrations/v1_22"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -43,6 +44,8 @@ var migrations = []*Migration{
 	NewMigration("create the forgejo_sem_ver table", forgejo_v1_20.CreateSemVerTable),
 	// v2 -> v3
 	NewMigration("create the forgejo_auth_token table", forgejo_v1_20.CreateAuthorizationTokenTable),
+	// v3 -> v4
+	NewMigration("Add default_permissions to repo_unit", forgejo_v1_22.AddDefaultPermissionsToRepoUnit),
 }
 
 // GetCurrentDBVersion returns the current Forgejo database version.

models/forgejo_migrations/v1_22/v4.go

@@ -0,0 +1,17 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"xorm.io/xorm"
+)
+
+func AddDefaultPermissionsToRepoUnit(x *xorm.Engine) error {
+	type RepoUnit struct {
+		ID                 int64
+		DefaultPermissions int `xorm:"NOT NULL DEFAULT 0"`
+	}
+
+	return x.Sync(&RepoUnit{})
+}

models/perm/access/repo_permission.go

@@ -33,6 +33,16 @@ func (p *Permission) IsAdmin() bool {
 	return p.AccessMode >= perm_model.AccessModeAdmin
 }
 
+// IsGloballyWriteable returns true if the unit is writeable by all users of the instance.
+func (p *Permission) IsGloballyWriteable(unitType unit.Type) bool {
+	for _, u := range p.Units {
+		if u.Type == unitType {
+			return u.DefaultPermissions == repo_model.UnitAccessModeWrite
+		}
+	}
+	return false
+}
+
 // HasAccess returns true if the current user has at least read access to any unit of this repository
 func (p *Permission) HasAccess() bool {
 	if p.UnitsMode == nil {
@@ -198,7 +208,19 @@ func GetUserRepoPermission(ctx context.Context, repo *repo_model.Repository, use
 	if err := repo.LoadOwner(ctx); err != nil {
 		return perm, err
 	}
+
 	if !repo.Owner.IsOrganization() {
+		// for a public repo, different repo units may have different default
+		// permissions for non-restricted users.
+		if !repo.IsPrivate && !user.IsRestricted && len(repo.Units) > 0 {
+			perm.UnitsMode = make(map[unit.Type]perm_model.AccessMode)
+			for _, u := range repo.Units {
+				if _, ok := perm.UnitsMode[u.Type]; !ok {
+					perm.UnitsMode[u.Type] = u.DefaultPermissions.ToAccessMode(perm.AccessMode)
+				}
+			}
+		}
+
 		return perm, nil
 	}
 
@@ -239,10 +261,12 @@ func GetUserRepoPermission(ctx context.Context, repo *repo_model.Repository, use
 			}
 		}
 
-		// for a public repo on an organization, a non-restricted user has read permission on non-team defined units.
+		// for a public repo on an organization, a non-restricted user should
+		// have the same permission on non-team defined units as the default
+		// permissions for the repo unit.
 		if !found && !repo.IsPrivate && !user.IsRestricted {
 			if _, ok := perm.UnitsMode[u.Type]; !ok {
-				perm.UnitsMode[u.Type] = perm_model.AccessModeRead
+				perm.UnitsMode[u.Type] = u.DefaultPermissions.ToAccessMode(perm_model.AccessModeRead)
 			}
 		}
 	}

models/repo/repo_unit.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/perm"
 	"code.gitea.io/gitea/models/unit"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/setting"
@@ -39,6 +40,35 @@ func (err ErrUnitTypeNotExist) Unwrap() error {
 	return util.ErrNotExist
 }
 
+// RepoUnitAccessMode specifies the users access mode to a repo unit
+type UnitAccessMode int
+
+const (
+	// UnitAccessModeUnset - no unit mode set
+	UnitAccessModeUnset UnitAccessMode = iota // 0
+	// UnitAccessModeNone no access
+	UnitAccessModeNone // 1
+	// UnitAccessModeRead read access
+	UnitAccessModeRead // 2
+	// UnitAccessModeWrite write access
+	UnitAccessModeWrite // 3
+)
+
+func (mode UnitAccessMode) ToAccessMode(modeIfUnset perm.AccessMode) perm.AccessMode {
+	switch mode {
+	case UnitAccessModeUnset:
+		return modeIfUnset
+	case UnitAccessModeNone:
+		return perm.AccessModeNone
+	case UnitAccessModeRead:
+		return perm.AccessModeRead
+	case UnitAccessModeWrite:
+		return perm.AccessModeWrite
+	default:
+		return perm.AccessModeNone
+	}
+}
+
 // RepoUnit describes all units of a repository
 type RepoUnit struct { //revive:disable-line:exported
 	ID                 int64
@@ -46,6 +76,7 @@ type RepoUnit struct { //revive:disable-line:exported
 	Type               unit.Type          `xorm:"INDEX(s)"`
 	Config             convert.Conversion `xorm:"TEXT"`
 	CreatedUnix        timeutil.TimeStamp `xorm:"INDEX CREATED"`
+	DefaultPermissions UnitAccessMode     `xorm:"NOT NULL DEFAULT 0"`
 }
 
 func init() {

models/repo/repo_unit_test.go

@@ -6,6 +6,8 @@ package repo
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/perm"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -28,3 +30,10 @@ func TestActionsConfig(t *testing.T) {
 	cfg.DisableWorkflow("test3.yaml")
 	assert.EqualValues(t, "test1.yaml,test2.yaml,test3.yaml", cfg.ToString())
 }
+
+func TestRepoUnitAccessMode(t *testing.T) {
+	assert.Equal(t, UnitAccessModeNone.ToAccessMode(perm.AccessModeAdmin), perm.AccessModeNone)
+	assert.Equal(t, UnitAccessModeRead.ToAccessMode(perm.AccessModeAdmin), perm.AccessModeRead)
+	assert.Equal(t, UnitAccessModeWrite.ToAccessMode(perm.AccessModeAdmin), perm.AccessModeWrite)
+	assert.Equal(t, UnitAccessModeUnset.ToAccessMode(perm.AccessModeRead), perm.AccessModeRead)
+}

options/locale/locale_en-US.ini

@@ -2036,6 +2036,7 @@ settings.branches.update_default_branch = Update Default Branch
 settings.branches.add_new_rule = Add New Rule
 settings.advanced_settings = Advanced Settings
 settings.wiki_desc = Enable Repository Wiki
+settings.wiki_globally_editable = Allow anyone to edit the Wiki
 settings.use_internal_wiki = Use Built-In Wiki
 settings.use_external_wiki = Use External Wiki
 settings.external_wiki_url = External Wiki URL

routers/web/repo/setting/setting.go

@@ -473,10 +473,17 @@ func SettingsPost(ctx *context.Context) {
 			})
 			deleteUnitTypes = append(deleteUnitTypes, unit_model.TypeWiki)
 		} else if form.EnableWiki && !form.EnableExternalWiki && !unit_model.TypeWiki.UnitGlobalDisabled() {
+			var wikiPermissions repo_model.UnitAccessMode
+			if form.GloballyWriteableWiki {
+				wikiPermissions = repo_model.UnitAccessModeWrite
+			} else {
+				wikiPermissions = repo_model.UnitAccessModeRead
+			}
 			units = append(units, repo_model.RepoUnit{
 				RepoID:             repo.ID,
 				Type:               unit_model.TypeWiki,
 				Config:             new(repo_model.UnitConfig),
+				DefaultPermissions: wikiPermissions,
 			})
 			deleteUnitTypes = append(deleteUnitTypes, unit_model.TypeExternalWiki)
 		} else {

services/forms/repo_form.go

@@ -140,6 +140,7 @@ type RepoSettingForm struct {
 	// Advanced settings
 	EnableCode                            bool
 	EnableWiki                            bool
+	GloballyWriteableWiki                 bool
 	EnableExternalWiki                    bool
 	ExternalWikiURL                       string
 	EnableIssues                          bool

templates/repo/settings/options.tmpl

@@ -318,6 +318,16 @@
 							<label>{{ctx.Locale.Tr "repo.settings.use_internal_wiki"}}</label>
 						</div>
 					</div>
+					{{if (not .Repository.IsPrivate)}}
+					<div class="field {{if (.Repository.UnitEnabled $.Context $.UnitTypeExternalWiki)}}disabled{{end}}">
+						<div class="field">
+							<div class="ui checkbox">
+								<input name="globally_writeable_wiki" type="checkbox" {{if .Permission.IsGloballyWriteable $.UnitTypeWiki}}checked{{end}}>
+								<label>{{ctx.Locale.Tr "repo.settings.wiki_globally_editable"}}</label>
+							</div>
+						</div>
+					</div>
+					{{end}}
 					<div class="field">
 						<div class="ui radio checkbox{{if $isExternalWikiGlobalDisabled}} disabled{{end}}"{{if $isExternalWikiGlobalDisabled}} data-tooltip-content="{{ctx.Locale.Tr "repo.unit_disabled"}}"{{end}}>
 							<input class="enable-system-radio" name="enable_external_wiki" type="radio" value="true" data-target="#external_wiki_box" {{if .Repository.UnitEnabled $.Context $.UnitTypeExternalWiki}}checked{{end}}>

tests/integration/api_wiki_test.go

@@ -4,12 +4,16 @@
 package integration
 
 import (
+	"context"
 	"encoding/base64"
 	"fmt"
 	"net/http"
 	"testing"
 
 	auth_model "code.gitea.io/gitea/models/auth"
+	repo_model "code.gitea.io/gitea/models/repo"
+	unit_model "code.gitea.io/gitea/models/unit"
+	"code.gitea.io/gitea/models/unittest"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/tests"
 
@@ -209,6 +213,53 @@ func TestAPIEditWikiPage(t *testing.T) {
 	MakeRequest(t, req, http.StatusOK)
 }
 
+func TestAPIEditOtherWikiPage(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// (drive-by-user) user, session, and token for a drive-by wiki editor
+	username := "drive-by-user"
+	req := NewRequestWithValues(t, "POST", "/user/sign_up", map[string]string{
+		"user_name": username,
+		"email":     "drive-by@example.com",
+		"password":  "examplePassword!1",
+		"retype":    "examplePassword!1",
+	})
+	MakeRequest(t, req, http.StatusSeeOther)
+	session := loginUserWithPassword(t, username, "examplePassword!1")
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteRepository)
+
+	// (user2) user for the user whose wiki we're going to edit (as drive-by-user)
+	otherUsername := "user2"
+
+	// Creating a new Wiki page on user2's repo as user1 fails
+	testCreateWiki := func(expectedStatusCode int) {
+		urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/wiki/new?token=%s", otherUsername, "repo1", token)
+		req := NewRequestWithJSON(t, "POST", urlStr, &api.CreateWikiPageOptions{
+			Title:         "Globally Edited Page",
+			ContentBase64: base64.StdEncoding.EncodeToString([]byte("Wiki page content for API unit tests")),
+			Message:       "",
+		})
+		session.MakeRequest(t, req, expectedStatusCode)
+	}
+	testCreateWiki(http.StatusForbidden)
+
+	// Update the repo settings for user2's repo to enable globally writeable wiki
+	ctx := context.Background()
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+	var units []repo_model.RepoUnit
+	units = append(units, repo_model.RepoUnit{
+		RepoID:             repo.ID,
+		Type:               unit_model.TypeWiki,
+		Config:             new(repo_model.UnitConfig),
+		DefaultPermissions: repo_model.UnitAccessModeWrite,
+	})
+	err := repo_model.UpdateRepositoryUnits(ctx, repo, units, nil)
+	assert.NoError(t, err)
+
+	// Creating a new Wiki page on user2's repo works now
+	testCreateWiki(http.StatusCreated)
+}
+
 func TestAPIListPageRevisions(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 	username := "user2"