docs/features/account-registration.md

@@ -78,7 +78,7 @@ recorded in `us_policy_acceptances` with `registration_type = account` and
 ## Flow (invite mode)
 1. Studio admin opens **Invites** (`manage_students`) and invites an email; an invite row is created storing the token's SHA-256 hash, and the registration link (with the raw token) is shown **once** in a notice. To re-send a lost link, revoke and re-invite.
 2. The invitee opens `[us_student_register]` with the token (`?us_invite=<token>`); the lookup hashes the submitted token and matches it against the stored hash.
-3. The form pre-fills the email and collects a display name and password, and renders the signup-scoped published policies, each with a required acceptance checkbox.
+3. The form shows the invited email **pre-filled and read-only** (the server always uses the invite's address on submit, so a tampered value is ignored) and collects a display name and password, and renders the signup-scoped published policies, each with a required acceptance checkbox. A token that is no longer redeemable (expired / accepted / revoked) renders the normal editable email field instead when open registration is on.
 4. On submit, the token is re-validated (hashed lookup); a `us_student` user is created, the policy acceptances are recorded (`account` type), the invite is marked `accepted`, and the user is logged in.
 
 ## Flow (self-approval mode)

src/Auth/RegistrationPage.php

@@ -45,6 +45,12 @@ class RegistrationPage {
 		$invite = '' !== $token ? $this->invites->findByToken( Invite::hashToken( $token ) ) : null;
 		$open   = $this->settings->openRegistrationEnabled();
 
+		// Only a redeemable invite fixes the form's email to the invited address.
+		// A stale token (expired / accepted / revoked) with open registration on
+		// must fall back to the normal editable email field, not show — and then
+		// fail to submit — the stale invite's address.
+		$inviteValid = null !== $invite && $invite->isAcceptable( current_time( 'mysql' ) );
+
 		$error       = '';
 		$successType = '';
 
@@ -65,7 +71,7 @@ class RegistrationPage {
 		$loginUrl = $this->loginUrl( Val::int( $atts['loginPageId'] ?? $atts['login_page_id'] ?? 0 ) );
 
 		$policyForms = $this->signupPolicies();
-		$canRegister = $open || ( null !== $invite && $invite->isAcceptable( current_time( 'mysql' ) ) );
+		$canRegister = $open || $inviteValid;
 
 		ob_start();
 		include USC_PLUGIN_DIR . 'templates/frontend/register-page.php';

templates/frontend/register-page.php

@@ -7,6 +7,7 @@ if (! defined('ABSPATH')) {
 
 /**
  * @var \Unsupervised\Schedular\Auth\Invite|null $invite
+ * @var bool   $inviteValid Whether $invite can still be redeemed — only then is the email fixed.
  * @var string $token Raw invite token from the request (only its hash is stored).
  * @var bool   $canRegister
  * @var bool   $open   Whether open (self-approval) registration is enabled.
@@ -43,7 +44,7 @@ if (! defined('ABSPATH')) {
 
                 <p>
                     <label for="us-reg-email"><?php esc_html_e('Email', 'unsupervised-schedular'); ?></label>
-                    <?php if ($invite !== null) : ?>
+                    <?php if ($inviteValid && $invite !== null) : ?>
                         <input type="email" id="us-reg-email" value="<?php echo esc_attr($invite->email); ?>" readonly>
                     <?php else : ?>
                         <input type="email" name="email" id="us-reg-email" autocomplete="email" required>

tests/Unit/Auth/RegistrationPageTest.php

@@ -56,8 +56,9 @@ class RegistrationPageTest extends TestCase
 
     protected function tearDown(): void
     {
-        $_POST = [];
+        $_POST    = [];
-        $_GET  = [];
+        $_GET     = [];
+        $_REQUEST = [];
         parent::tearDown();
     }
 
@@ -176,6 +177,47 @@ class RegistrationPageTest extends TestCase
         self::assertStringContainsString('<form', $html);
     }
 
+    public function testValidInviteRendersEmailPrefilledAndLocked(): void
+    {
+        $_REQUEST = ['us_invite' => 'raw-token'];
+        $this->stubRenderContext();
+
+        $invite = new Invite(email: '[email protected]', token: 'hash', createdAt: '2024-01-01 00:00:00', id: 9);
+        $this->ctx['invites']->shouldReceive('findByToken')
+            ->once()
+            ->with(Invite::hashToken('raw-token'))
+            ->andReturn($invite);
+
+        $html = $this->ctx['page']->render([]);
+
+        // The invited address is shown read-only; there is no editable email input.
+        self::assertStringContainsString('value="[email protected]" readonly', $html);
+        self::assertStringNotContainsString('name="email"', $html);
+    }
+
+    public function testStaleInviteWithOpenRegistrationShowsEditableEmail(): void
+    {
+        $_REQUEST = ['us_invite' => 'raw-token'];
+        $this->stubRenderContext();
+
+        // Already-redeemed invite: not acceptable, so the open-registration form
+        // must collect an email rather than showing the stale locked address.
+        $invite = new Invite(
+            email: '[email protected]',
+            token: 'hash',
+            status: Invite::STATUS_ACCEPTED,
+            createdAt: '2024-01-01 00:00:00',
+            id: 9
+        );
+        $this->ctx['invites']->shouldReceive('findByToken')->once()->andReturn($invite);
+
+        $html = $this->ctx['page']->render([]);
+
+        self::assertStringContainsString('name="email"', $html);
+        self::assertStringNotContainsString('[email protected]', $html);
+        self::assertStringNotContainsString('readonly', $html);
+    }
+
     public function testRejectsWhenARequiredPolicyIsUnaccepted(): void
     {
         $_POST = [ 'password' => 'password123', 'display_name' => 'Ada', 'email' => '[email protected]' ];