fix(login): remove duplicate loginName/user_autofocus block that clobbered LDAP resolution

A second if/else block after the alt_login assignment was unconditionally
overwriting $parameters['loginName'] with the raw $user input, silently
discarding the getUserName() resolution done in the first block for LDAP
accounts whose internal username is a UUID. The first block already handles
all cases correctly; the duplicate was dead code with a functional side-effect.

Adds a regression test (testShowLoginFormLdapUsernameResolutionNotClobbered)
that passes an internal UUID as $user and asserts loginName is the resolved
display name, not the raw UUID.

Signed-off-by: Thomas Müller <1005065+DeepDiver1975@users.noreply.github.com>

Author: DeepDiver1975

core/Controller/LoginController.php

@@ -193,14 +193,6 @@ public function showLoginForm($user, $redirect_url, $remember_login) {
 		$parameters['rememberLoginAllowed'] = OC_Util::rememberLoginAllowed();
 		$parameters['rememberLoginState'] = !empty($remember_login) ? $remember_login : 0;
 
-		if ($user !== null && $user !== '') {
-			$parameters['loginName'] = $user;
-			$parameters['user_autofocus'] = false;
-		} else {
-			$parameters['loginName'] = '';
-			$parameters['user_autofocus'] = true;
-		}
-
 		/**
 		 * If redirect_url is not empty and remember_login is null and
 		 * user not logged in and check if the string

tests/Core/Controller/LoginControllerTest.php

@@ -388,6 +388,44 @@ public function testShowLoginFormWithPasswordResetOptionAlwaysTrueWhenNoLostPass
 		$this->assertEquals($expectedResponse, $this->loginController->showLoginForm('LdapUser', '', ''));
 	}
 
+	/**
+	 * LDAP accounts with a UUID internal username must have loginName resolved to the
+	 * human-readable display name returned by getUserName(). A duplicate loginName block
+	 * that existed after the alt_login assignment was clobbering this resolved value back
+	 * to the raw internal username — this test is the regression guard for that removal.
+	 */
+	public function testShowLoginFormLdapUsernameResolutionNotClobbered() {
+		$this->userSession
+			->expects($this->once())
+			->method('isLoggedIn')
+			->willReturn(false);
+		$this->config
+			->expects($this->exactly(3))
+			->method('getSystemValue')
+			->willReturnMap([
+				['lost_password_link', false],
+				['login.alternatives', '', ''],
+				['strict_login_enforced', false],
+			]);
+		$user = $this->createMock(IUser::class);
+		$user->method('getUserName')->willReturn('john.doe');
+		$this->userManager
+			->expects($this->once())
+			->method('get')
+			->with('some-internal-uuid-1234')
+			->willReturn($user);
+
+		$this->licenseManager->method('getLicenseMessageFor')
+			->willReturn([
+				'license_state' => ILicenseManager::LICENSE_STATE_MISSING
+			]);
+
+		$response = $this->loginController->showLoginForm('some-internal-uuid-1234', '', '');
+		$params = $response->getParams();
+		$this->assertSame('john.doe', $params['loginName'], 'LDAP username must be resolved to getUserName(), not the raw internal ID');
+		$this->assertFalse($params['user_autofocus']);
+	}
+
 	/**
 	 * Verify user enumeration fix: a non-existent user and an LDAP user (canChangePassword=false)
 	 * must both yield canResetPassword=true when lost_password_link is empty, making the