perf: Use more performant way to obtain and check the email as a login name with token login

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/private/User/Session.php

@@ -456,8 +456,17 @@ class Session implements IUserSession, Emitter {
 				$this->handleLoginFailed($throttler, $currentDelay, $remoteAddress, $user, $password);
 				return false;
 			}
-			$users = $this->manager->getByEmail($user);
-			if (!(\count($users) === 1 && $this->login($users[0]->getUID(), $password))) {
+
+			if ($isTokenPassword) {
+				$dbToken = $this->tokenProvider->getToken($password);
+				$userFromToken = $this->manager->get($dbToken->getUID());
+				$isValidEmailLogin = $userFromToken->getEMailAddress() === $user;
+			} else {
+				$users = $this->manager->getByEmail($user);
+				$isValidEmailLogin = (\count($users) === 1 && $this->login($users[0]->getUID(), $password));
+			}
+
+			if (!$isValidEmailLogin) {
 				$this->handleLoginFailed($throttler, $currentDelay, $remoteAddress, $user, $password);
 				return false;
 			}

tests/lib/User/SessionTest.php

@@ -1110,7 +1110,7 @@ class SessionTest extends \Test\TestCase {
 
 		$userSession->expects($this->once())
 			->method('isTokenPassword')
-			->willReturn(true);
+			->willReturn(false);
 		$userSession->expects($this->once())
 			->method('login')
 			->with('john@foo.bar', 'I-AM-AN-PASSWORD')