fix(settings): Handle email change restriction separately from display name change restriction

Co-authored-by: provokateurin <kate@provokateurin.de>
Co-authored-by: Ferdinand Thiessen <opensource@fthiessen.de>
Co-authored-by: Louis <louis@chmn.me>
Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

7 files changed, 128 insertions, 30 deletions

diff --git a/apps/provisioning_api/lib/Controller/UsersController.php b/apps/provisioning_api/lib/Controller/UsersController.php
index 6b22a010a8c..4b3db45f518 100644
--- a/apps/provisioning_api/lib/Controller/UsersController.php
+++ b/apps/provisioning_api/lib/Controller/UsersController.php
@@ -748,14 +748,16 @@ class UsersController extends AUserDataOCSController {
 			$targetUser = $currentLoggedInUser;
 		}
 
-		// Editing self (display, email)
-		if ($this->config->getSystemValue('allow_user_to_change_display_name', true) !== false) {
-			if (
-				$targetUser->getBackend() instanceof ISetDisplayNameBackend
-				|| $targetUser->getBackend()->implementsActions(Backend::SET_DISPLAYNAME)
-			) {
-				$permittedFields[] = IAccountManager::PROPERTY_DISPLAYNAME;
-			}
+		$allowDisplayNameChange = $this->config->getSystemValue('allow_user_to_change_display_name', true);
+		if ($allowDisplayNameChange === true && (
+			$targetUser->getBackend() instanceof ISetDisplayNameBackend
+			|| $targetUser->getBackend()->implementsActions(Backend::SET_DISPLAYNAME)
+		)) {
+			$permittedFields[] = IAccountManager::PROPERTY_DISPLAYNAME;
+		}
+
+		// Fallback to display name value to avoid changing behavior with the new option.
+		if ($this->config->getSystemValue('allow_user_to_change_email', $allowDisplayNameChange)) {
 			$permittedFields[] = IAccountManager::PROPERTY_EMAIL;
 		}
 
@@ -907,15 +909,17 @@ class UsersController extends AUserDataOCSController {
 
 		$permittedFields = [];
 		if ($targetUser->getUID() === $currentLoggedInUser->getUID()) {
-			// Editing self (display, email)
-			if ($this->config->getSystemValue('allow_user_to_change_display_name', true) !== false) {
-				if (
-					$targetUser->getBackend() instanceof ISetDisplayNameBackend
-					|| $targetUser->getBackend()->implementsActions(Backend::SET_DISPLAYNAME)
-				) {
-					$permittedFields[] = self::USER_FIELD_DISPLAYNAME;
-					$permittedFields[] = IAccountManager::PROPERTY_DISPLAYNAME;
-				}
+			$allowDisplayNameChange = $this->config->getSystemValue('allow_user_to_change_display_name', true);
+			if ($allowDisplayNameChange !== false && (
+				$targetUser->getBackend() instanceof ISetDisplayNameBackend
+				|| $targetUser->getBackend()->implementsActions(Backend::SET_DISPLAYNAME)
+			)) {
+				$permittedFields[] = self::USER_FIELD_DISPLAYNAME;
+				$permittedFields[] = IAccountManager::PROPERTY_DISPLAYNAME;
+			}
+
+			// Fallback to display name value to avoid changing behavior with the new option.
+			if ($this->config->getSystemValue('allow_user_to_change_email', $allowDisplayNameChange)) {
 				$permittedFields[] = IAccountManager::PROPERTY_EMAIL;
 			}
 
diff --git a/apps/provisioning_api/tests/Controller/UsersControllerTest.php b/apps/provisioning_api/tests/Controller/UsersControllerTest.php
index 439ee0be250..7d4f99356b3 100644
--- a/apps/provisioning_api/tests/Controller/UsersControllerTest.php
+++ b/apps/provisioning_api/tests/Controller/UsersControllerTest.php
@@ -42,6 +42,7 @@ use OCP\User\Backend\ISetDisplayNameBackend;
 use OCP\UserInterface;
 use PHPUnit\Framework\MockObject\MockObject;
 use Psr\Log\LoggerInterface;
+use RuntimeException;
 use Test\TestCase;
 
 class UsersControllerTest extends TestCase {
@@ -1668,6 +1669,8 @@ class UsersControllerTest extends TestCase {
 			->method('getBackend')
 			->willReturn($backend);
 
+		$this->config->method('getSystemValue')->willReturnCallback(fn (string $key, mixed $default) => $default);
+
 		$this->assertEquals([], $this->api->editUser('UserToEdit', 'email', 'demo@nextcloud.com')->getData());
 	}
 
@@ -1862,6 +1865,8 @@ class UsersControllerTest extends TestCase {
 			->method('getBackend')
 			->willReturn($backend);
 
+		$this->config->method('getSystemValue')->willReturnCallback(fn (string $key, mixed $default) => $default);
+
 		$this->api->editUser('UserToEdit', 'email', 'demo.org');
 	}
 
@@ -4260,7 +4265,8 @@ class UsersControllerTest extends TestCase {
 
 	public function dataGetEditableFields() {
 		return [
-			[false, ISetDisplayNameBackend::class, [
+			[false, true, ISetDisplayNameBackend::class, [
+				IAccountManager::PROPERTY_EMAIL,
 				IAccountManager::COLLECTION_EMAIL,
 				IAccountManager::PROPERTY_PHONE,
 				IAccountManager::PROPERTY_ADDRESS,
@@ -4274,7 +4280,22 @@ class UsersControllerTest extends TestCase {
 				IAccountManager::PROPERTY_PROFILE_ENABLED,
 				IAccountManager::PROPERTY_PRONOUNS,
 			]],
-			[true, ISetDisplayNameBackend::class, [
+			[true, false, ISetDisplayNameBackend::class, [
+				IAccountManager::PROPERTY_DISPLAYNAME,
+				IAccountManager::COLLECTION_EMAIL,
+				IAccountManager::PROPERTY_PHONE,
+				IAccountManager::PROPERTY_ADDRESS,
+				IAccountManager::PROPERTY_WEBSITE,
+				IAccountManager::PROPERTY_TWITTER,
+				IAccountManager::PROPERTY_FEDIVERSE,
+				IAccountManager::PROPERTY_ORGANISATION,
+				IAccountManager::PROPERTY_ROLE,
+				IAccountManager::PROPERTY_HEADLINE,
+				IAccountManager::PROPERTY_BIOGRAPHY,
+				IAccountManager::PROPERTY_PROFILE_ENABLED,
+				IAccountManager::PROPERTY_PRONOUNS,
+			]],
+			[true, true, ISetDisplayNameBackend::class, [
 				IAccountManager::PROPERTY_DISPLAYNAME,
 				IAccountManager::PROPERTY_EMAIL,
 				IAccountManager::COLLECTION_EMAIL,
@@ -4290,7 +4311,21 @@ class UsersControllerTest extends TestCase {
 				IAccountManager::PROPERTY_PROFILE_ENABLED,
 				IAccountManager::PROPERTY_PRONOUNS,
 			]],
-			[true, UserInterface::class, [
+			[false, false, ISetDisplayNameBackend::class, [
+				IAccountManager::COLLECTION_EMAIL,
+				IAccountManager::PROPERTY_PHONE,
+				IAccountManager::PROPERTY_ADDRESS,
+				IAccountManager::PROPERTY_WEBSITE,
+				IAccountManager::PROPERTY_TWITTER,
+				IAccountManager::PROPERTY_FEDIVERSE,
+				IAccountManager::PROPERTY_ORGANISATION,
+				IAccountManager::PROPERTY_ROLE,
+				IAccountManager::PROPERTY_HEADLINE,
+				IAccountManager::PROPERTY_BIOGRAPHY,
+				IAccountManager::PROPERTY_PROFILE_ENABLED,
+				IAccountManager::PROPERTY_PRONOUNS,
+			]],
+			[false, true, UserInterface::class, [
 				IAccountManager::PROPERTY_EMAIL,
 				IAccountManager::COLLECTION_EMAIL,
 				IAccountManager::PROPERTY_PHONE,
@@ -4305,6 +4340,49 @@ class UsersControllerTest extends TestCase {
 				IAccountManager::PROPERTY_PROFILE_ENABLED,
 				IAccountManager::PROPERTY_PRONOUNS,
 			]],
+			[true, false, UserInterface::class, [
+				IAccountManager::COLLECTION_EMAIL,
+				IAccountManager::PROPERTY_PHONE,
+				IAccountManager::PROPERTY_ADDRESS,
+				IAccountManager::PROPERTY_WEBSITE,
+				IAccountManager::PROPERTY_TWITTER,
+				IAccountManager::PROPERTY_FEDIVERSE,
+				IAccountManager::PROPERTY_ORGANISATION,
+				IAccountManager::PROPERTY_ROLE,
+				IAccountManager::PROPERTY_HEADLINE,
+				IAccountManager::PROPERTY_BIOGRAPHY,
+				IAccountManager::PROPERTY_PROFILE_ENABLED,
+				IAccountManager::PROPERTY_PRONOUNS,
+			]],
+			[true, true, UserInterface::class, [
+				IAccountManager::PROPERTY_EMAIL,
+				IAccountManager::COLLECTION_EMAIL,
+				IAccountManager::PROPERTY_PHONE,
+				IAccountManager::PROPERTY_ADDRESS,
+				IAccountManager::PROPERTY_WEBSITE,
+				IAccountManager::PROPERTY_TWITTER,
+				IAccountManager::PROPERTY_FEDIVERSE,
+				IAccountManager::PROPERTY_ORGANISATION,
+				IAccountManager::PROPERTY_ROLE,
+				IAccountManager::PROPERTY_HEADLINE,
+				IAccountManager::PROPERTY_BIOGRAPHY,
+				IAccountManager::PROPERTY_PROFILE_ENABLED,
+				IAccountManager::PROPERTY_PRONOUNS,
+			]],
+			[false, false, UserInterface::class, [
+				IAccountManager::COLLECTION_EMAIL,
+				IAccountManager::PROPERTY_PHONE,
+				IAccountManager::PROPERTY_ADDRESS,
+				IAccountManager::PROPERTY_WEBSITE,
+				IAccountManager::PROPERTY_TWITTER,
+				IAccountManager::PROPERTY_FEDIVERSE,
+				IAccountManager::PROPERTY_ORGANISATION,
+				IAccountManager::PROPERTY_ROLE,
+				IAccountManager::PROPERTY_HEADLINE,
+				IAccountManager::PROPERTY_BIOGRAPHY,
+				IAccountManager::PROPERTY_PROFILE_ENABLED,
+				IAccountManager::PROPERTY_PRONOUNS,
+			]],
 		];
 	}
 
@@ -4315,13 +4393,12 @@ class UsersControllerTest extends TestCase {
 	 * @param string $userBackend
 	 * @param array $expected
 	 */
-	public function testGetEditableFields(bool $allowedToChangeDisplayName, string $userBackend, array $expected): void {
-		$this->config
-			->method('getSystemValue')
-			->with(
-				$this->equalTo('allow_user_to_change_display_name'),
-				$this->anything()
-			)->willReturn($allowedToChangeDisplayName);
+	public function testGetEditableFields(bool $allowedToChangeDisplayName, bool $allowedToChangeEmail, string $userBackend, array $expected): void {
+		$this->config->method('getSystemValue')->willReturnCallback(fn (string $key, mixed $default) => match ($key) {
+			'allow_user_to_change_display_name' => $allowedToChangeDisplayName,
+			'allow_user_to_change_email' => $allowedToChangeEmail,
+			default => throw new RuntimeException('Unexpected system config key: ' . $key),
+		});
 
 		$user = $this->createMock(IUser::class);
 		$this->userSession->method('getUser')
diff --git a/apps/settings/lib/Settings/Personal/PersonalInfo.php b/apps/settings/lib/Settings/Personal/PersonalInfo.php
index 9860ec5c9c7..1032f97361b 100644
--- a/apps/settings/lib/Settings/Personal/PersonalInfo.php
+++ b/apps/settings/lib/Settings/Personal/PersonalInfo.php
@@ -114,6 +114,7 @@ class PersonalInfo implements ISettings {
 		$accountParameters = [
 			'avatarChangeSupported' => $user->canChangeAvatar(),
 			'displayNameChangeSupported' => $user->canChangeDisplayName(),
+			'emailChangeSupported' => $user->canChangeEmail(),
 			'federationEnabled' => $federationEnabled,
 			'lookupServerUploadEnabled' => $lookupServerUploadEnabled,
 		];
diff --git a/apps/settings/src/components/PersonalInfo/EmailSection/EmailSection.vue b/apps/settings/src/components/PersonalInfo/EmailSection/EmailSection.vue
index 8fd17922724..f9674a3163b 100644
--- a/apps/settings/src/components/PersonalInfo/EmailSection/EmailSection.vue
+++ b/apps/settings/src/components/PersonalInfo/EmailSection/EmailSection.vue
@@ -13,7 +13,7 @@
 			:scope.sync="primaryEmail.scope"
 			@add-additional="onAddAdditionalEmail" />
 
-		<template v-if="displayNameChangeSupported">
+		<template v-if="emailChangeSupported">
 			<Email :input-id="inputId"
 				:primary="true"
 				:scope.sync="primaryEmail.scope"
@@ -56,7 +56,7 @@ import { validateEmail } from '../../../utils/validate.js'
 import { handleError } from '../../../utils/handlers.ts'
 
 const { emailMap: { additionalEmails, primaryEmail, notificationEmail } } = loadState('settings', 'personalInfoParameters', {})
-const { displayNameChangeSupported } = loadState('settings', 'accountParameters', {})
+const { emailChangeSupported } = loadState('settings', 'accountParameters', {})
 
 export default {
 	name: 'EmailSection',
@@ -70,7 +70,7 @@ export default {
 		return {
 			accountProperty: ACCOUNT_PROPERTY_READABLE_ENUM.EMAIL,
 			additionalEmails: additionalEmails.map(properties => ({ ...properties, key: this.generateUniqueKey() })),
-			displayNameChangeSupported,
+			emailChangeSupported,
 			primaryEmail: { ...primaryEmail, readable: NAME_READABLE_ENUM[primaryEmail.name] },
 			notificationEmail,
 		}
diff --git a/lib/private/User/LazyUser.php b/lib/private/User/LazyUser.php
index 9eb5f9afb25..715265f6a39 100644
--- a/lib/private/User/LazyUser.php
+++ b/lib/private/User/LazyUser.php
@@ -112,6 +112,10 @@ class LazyUser implements IUser {
 		return $this->getUser()->canChangeDisplayName();
 	}
 
+	public function canChangeEmail(): bool {
+		return $this->getUser()->canChangeEmail();
+	}
+
 	public function isEnabled() {
 		return $this->getUser()->isEnabled();
 	}
diff --git a/lib/private/User/User.php b/lib/private/User/User.php
index 3d5c13d4431..f04977314e2 100644
--- a/lib/private/User/User.php
+++ b/lib/private/User/User.php
@@ -447,6 +447,11 @@ class User implements IUser {
 		return $this->backend->implementsActions(Backend::SET_DISPLAYNAME);
 	}
 
+	public function canChangeEmail(): bool {
+		// Fallback to display name value to avoid changing behavior with the new option.
+		return $this->config->getSystemValueBool('allow_user_to_change_email', $this->config->getSystemValueBool('allow_user_to_change_display_name', true));
+	}
+
 	/**
 	 * check if the user is enabled
 	 *
diff --git a/lib/public/IUser.php b/lib/public/IUser.php
index b4808ec045a..227e4f902c7 100644
--- a/lib/public/IUser.php
+++ b/lib/public/IUser.php
@@ -150,6 +150,13 @@ interface IUser {
 	public function canChangeDisplayName();
 
 	/**
+	 * Check if the backend supports changing email
+	 *
+	 * @since 32.0.0
+	 */
+	public function canChangeEmail(): bool;
+
+	/**
 	 * check if the user is enabled
 	 *
 	 * @return bool