refactor: add null guards for psalm

lib/Controller/AvatarsController.php

@@ -85,9 +85,13 @@ public function image(string $email): Response {
 		}
 
 		$imageData = $this->avatarService->getAvatarImage($email, $this->uid);
+
+		if ($imageData === null) {
+			return $this->noAvatarFoundResponse();
+		}
 		[$avatar, $image] = $imageData;
 
-		if (is_null($imageData) || !$avatar->isExternal()) {
+		if (!$avatar->isExternal()) {
 			// This could happen if the cache invalidated meanwhile
 			return $this->noAvatarFoundResponse();
 		}

lib/Controller/MessageApiController.php

@@ -296,10 +296,14 @@
 		$json['rawUrl'] = $this->urlGenerator->linkToOCSRouteAbsolute('mail.messageApi.getRaw', ['id' => $id]);
 
 		if (!$loadBody) {
-			return new DataResponse($json, Http::STATUS_PARTIAL_CONTENT);
+			/** @var DataResponse<Http::STATUS_PARTIAL_CONTENT, MailMessageApiResponse, array{}> $response */
+			$response = new DataResponse($json, Http::STATUS_PARTIAL_CONTENT);
+			return $response;
 		}
 
-		return new DataResponse($json, Http::STATUS_OK);
+		/** @var DataResponse<Http::STATUS_OK, MailMessageApiResponse, array{}> $response */
+		$response = new DataResponse($json, Http::STATUS_OK);
+		return $response;
 	}
 
 	/**
@@ -382,6 +386,10 @@
 	#[NoAdminRequired]
 	#[TrapError]
 	public function getAttachment(int $id, string $attachmentId): DataResponse {
+		if ($this->userId === null) {
+			return new DataResponse('Account not found.', Http::STATUS_NOT_FOUND);
+		}
+
 		try {
 			$message = $this->mailManager->getMessage($this->userId, $id);
 			$mailbox = $this->mailManager->getMailbox($this->userId, $message->getMailboxId());
@@ -407,20 +415,24 @@
 
 		// Body party and embedded messages do not have a name
 		if ($attachment->getName() === null) {
-			return new DataResponse([
+			/** @var DataResponse<Http::STATUS_OK, MailMessageApiAttachment, array{}> $response */
+			$response = new DataResponse([
 				'name' => $attachmentId . '.eml',
 				'mime' => $attachment->getType(),
 				'size' => $attachment->getSize(),
 				'content' => $attachment->getContent()
 			]);
+			return $response;
 		}
 
-		return new DataResponse([
+		/** @var DataResponse<Http::STATUS_OK, MailMessageApiAttachment, array{}> $response */
+		$response = new DataResponse([
 			'name' => $attachment->getName(),
 			'mime' => $attachment->getType(),
 			'size' => $attachment->getSize(),
 			'content' => $attachment->getContent()
 		]);
+		return $response;
 	}
 
 	/**
@@ -444,13 +456,13 @@
 			];
 			$file = new UploadedFile($filedata);
 			try {
 				$attachment = $this->attachmentService->addFile($this->userId, $file);
 				$messageAttachments[] = $attachment;
 			} catch (UploadException $e) {
 				$this->logger->error('Could not convert attachment to local attachment.', ['exception' => $e]);
 				foreach ($messageAttachments as $attachment) {
 					// Handle possible dangling local attachments
 					$this->attachmentService->deleteAttachment($this->userId, $attachment->getId());
 				}
 				throw $e;
 			}

lib/Controller/MessagesController.php

@@ -349,7 +349,7 @@
 			return false;
 		}
 		return $this->trustedSenderService->isTrusted(
 			$this->currentUserId,
 			$email
 		);
 	}
@@ -380,7 +380,7 @@
 			return new JSONResponse([], Http::STATUS_NOT_FOUND);
 		}
 
-		return new JSONResponse($this->mailManager->getThread($account, $message->getThreadRootId()));
+		return new JSONResponse($this->mailManager->getThread($account, (string)$message->getThreadRootId()));
 	}
 
 	/**
@@ -589,7 +589,7 @@
 		}
 
 		return new AttachmentDownloadResponse(
-			$source,
+			$source ?? '',
 			$message->getSubject() . '.eml',
 			'message/rfc822',
 		);
@@ -721,7 +721,8 @@
 		);
 
 		// Body party and embedded messages do not have a name
-		if ($attachment->getName() === null) {
+		$attachmentName = $attachment->getName();
+		if ($attachmentName === null) {
 			return new AttachmentDownloadResponse(
 				$attachment->getContent(),
 				$this->l10n->t('Embedded message %s', [
@@ -732,7 +733,7 @@
 		}
 		return new AttachmentDownloadResponse(
 			$attachment->getContent(),
-			$attachment->getName(),
+			$attachmentName,
 			$attachment->getType()
 		);
 	}
@@ -766,7 +767,7 @@
 		$zip = new ZipResponse($this->request, 'attachments');
 
 		foreach ($attachments as $attachment) {
-			$fileName = $attachment->getName();
+			$fileName = $attachment->getName() ?? '';
 			$fh = fopen('php://temp', 'r+');
 			if ($fh === false) {
 				continue;
@@ -800,6 +801,9 @@
 		if ($this->currentUserId === null) {
 			return new JSONResponse([], Http::STATUS_UNAUTHORIZED);
 		}
+		if ($this->userFolder === null) {
+			return new JSONResponse([], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
 		try {
 			$message = $this->mailManager->getMessage($this->currentUserId, $id);
 			$mailbox = $this->mailManager->getMailbox($this->currentUserId, $message->getMailboxId());
@@ -831,7 +835,7 @@
 			]) . '.eml';
 			$fileParts = pathinfo($fileName);
 			$fileName = $fileParts['filename'];
-			$fileExtension = $fileParts['extension'];
+			$fileExtension = $fileParts['extension'] ?? '';
 			$fullPath = "$targetPath/$fileName.$fileExtension";
 			$counter = 2;
 			while ($this->userFolder->nodeExists($fullPath)) {
@@ -995,7 +999,7 @@
 			return new JSONResponse([], Http::STATUS_FORBIDDEN);
 		}
 		try {
-			$replies = array_values($this->aiIntegrationService->getSmartReply($account, $mailbox, $message, $this->currentUserId));
+			$replies = array_values($this->aiIntegrationService->getSmartReply($account, $mailbox, $message, $this->currentUserId) ?? []);
 		} catch (ServiceException $e) {
 			$this->logger->error('Smart reply failed: ' . $e->getMessage(), [
 				'exception' => $e,

lib/Controller/PageController.php

@@ -135,6 +135,17 @@
 	 * @return TemplateResponse renders the index page
 	 */
 	public function index(): TemplateResponse {
+		if ($this->currentUserId === null) {
+			// This should not happen as the route requires authentication,
+			// but handle it defensively.
+			return new TemplateResponse($this->appName, 'index');
+		}
+
+		$user = $this->userSession->getUser();
+		if ($user === null) {
+			return new TemplateResponse($this->appName, 'index');
+		}
+
 		if (class_exists(LoadViewer::class)) {
 			$this->dispatcher->dispatchTyped(new LoadViewer());
 		}
@@ -216,7 +227,6 @@
 			$passwordIsUnavailable,
 		);
 
-		$user = $this->userSession->getUser();
 		$response = new TemplateResponse($this->appName, 'index');
 		$this->initialStateService->provideInitialState('preferences', [
 			'attachment-size-limit' => $this->config->getSystemValue('app.mail.attachment-size-limit', 0),
@@ -235,7 +245,7 @@
 		]);
 		$this->initialStateService->provideInitialState(
 			'prefill_displayName',
 			$this->userManager->getDisplayName($this->currentUserId),
 		);
 		$this->initialStateService->provideInitialState(
 			'importance_classification_default',
@@ -456,14 +466,14 @@
 	public function compose(string $uri): RedirectResponse {
 		$parts = parse_url($uri);
 		$params = [];
-		if (isset($parts['path'])) {
+		if (is_array($parts) && isset($parts['path'])) {
 			$params['to'] = $parts['path'];
 		}
-		if (isset($parts['query'])) {
-			$parts = explode('&', $parts['query']);
-			foreach ($parts as $part) {
+		if (is_array($parts) && isset($parts['query'])) {
+			$queryParts = explode('&', $parts['query']);
+			foreach ($queryParts as $part) {
 				$pair = explode('=', $part, 2);
-				$params[strtolower($pair[0])] = urldecode($pair[1]);
+				$params[strtolower($pair[0])] = urldecode($pair[1] ?? '');
 			}
 		}
 

lib/Controller/SmimeCertificatesController.php

@@ -105,7 +105,7 @@ public function create(): JsonResponse {
 		}
 
 		$certificateFile = new UploadedFile($attachedCertificate);
-		$certificateData = file_get_contents($certificateFile->getTempPath());
+		$certificateData = file_get_contents($certificateFile->getTempPath() ?? '');
 		if ($certificateData === false) {
 			return JsonResponse::fail(
 				'Could not read certificate file',
@@ -116,7 +116,7 @@ public function create(): JsonResponse {
 		$privateKeyData = null;
 		if ($attachedPrivateKey !== null) {
 			$privateKeyFile = new UploadedFile($attachedPrivateKey);
-			$privateKeyData = file_get_contents($privateKeyFile->getTempPath());
+			$privateKeyData = file_get_contents($privateKeyFile->getTempPath() ?? '');
 			if ($privateKeyData === false) {
 				return JsonResponse::fail(
 					'Could not read private key file',

lib/Controller/ThreadController.php

@@ -73,12 +73,16 @@
 			return new JSONResponse([], Http::STATUS_FORBIDDEN);
 		}
 
+		$threadRootId = $message->getThreadRootId();
+		if ($threadRootId === null) {
+			return new JSONResponse([], Http::STATUS_NOT_FOUND);
+		}
 		$this->mailManager->moveThread(
 			$srcAccount,
 			$srcMailbox,
 			$dstAccount,
 			$dstMailbox,
-			$message->getThreadRootId()
+			$threadRootId
 		);
 
 		return new JSONResponse();
@@ -149,14 +153,15 @@
 		} catch (DoesNotExistException $e) {
 			return new JSONResponse([], Http::STATUS_FORBIDDEN);
 		}
-		if (empty($message->getThreadRootId())) {
+		if ($message->getThreadRootId() === null || $message->getThreadRootId() === '') {
 			return new JSONResponse([], Http::STATUS_NOT_FOUND);
 		}
-		$thread = $this->mailManager->getThread($account, $message->getThreadRootId());
+		$threadRootId = $message->getThreadRootId();
+		$thread = $this->mailManager->getThread($account, $threadRootId);
 		try {
 			$summary = $this->aiIntergrationsService->summarizeThread(
 				$account,
-				$message->getThreadRootId(),
+				$threadRootId,
 				$thread,
 				$this->currentUserId,
 			);
@@ -181,13 +186,14 @@
 		} catch (DoesNotExistException $e) {
 			return new JSONResponse([], Http::STATUS_FORBIDDEN);
 		}
-		if (empty($message->getThreadRootId())) {
+		if ($message->getThreadRootId() === null || $message->getThreadRootId() === '') {
 			return new JSONResponse([], Http::STATUS_NOT_FOUND);
 		}
-		$thread = $this->mailManager->getThread($account, $message->getThreadRootId());
+		$threadRootId = $message->getThreadRootId();
+		$thread = $this->mailManager->getThread($account, $threadRootId);
 		$data = $this->aiIntergrationsService->generateEventData(
 			$account,
-			$message->getThreadRootId(),
+			$threadRootId,
 			$thread,
 			$this->currentUserId,
 		);
@@ -214,10 +220,14 @@
 			return new JSONResponse([], Http::STATUS_FORBIDDEN);
 		}
 
+		$threadRootId = $message->getThreadRootId();
+		if ($threadRootId === null) {
+			return new JSONResponse([], Http::STATUS_NOT_FOUND);
+		}
 		$this->mailManager->deleteThread(
 			$account,
 			$mailbox,
-			$message->getThreadRootId()
+			$threadRootId
 		);
 
 		return new JSONResponse();