Detect aborted connection in OC\Files\View and stop writing data to the

 output buffer

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

Author: come-nc

lib/private/Files/View.php

@@ -428,6 +428,7 @@ public function readfile($path) {
 			$chunkSize = 524288; // 512 kB chunks
 			while (!feof($handle)) {
 				echo fread($handle, $chunkSize);
+				$this->checkConnectionStatus();
 				flush();
 			}
 			fclose($handle);
@@ -480,6 +481,7 @@ public function readfilePart($path, $from, $to) {
 						$len = $chunkSize;
 					}
 					echo fread($handle, $len);
+					$this->checkConnectionStatus();
 					flush();
 				}
 				return ftell($handle) - $from;
@@ -490,6 +492,14 @@ public function readfilePart($path, $from, $to) {
 		return false;
 	}
 
+
+	private function checkConnectionStatus(): void {
+		$connectionStatus = \connection_status();
+		if ($connectionStatus !== 0) {
+			throw new \RuntimeException("Connection lost. Status: $connectionStatus");
+		}
+	}
+
 	/**
 	 * @param string $path
 	 * @return mixed
@@ -1053,7 +1063,6 @@ public function toTmpFile($path) {
 	public function fromTmpFile($tmpFile, $path) {
 		$this->assertPathLength($path);
 		if (Filesystem::isValidPath($path)) {
-
 			// Get directory that the file is going into
 			$filePath = dirname($path);
 
@@ -1809,7 +1818,6 @@ private function assertPathLength($path) {
 	 * @return boolean
 	 */
 	private function targetIsNotShared(IStorage $targetStorage, string $targetInternalPath) {
-
 		// note: cannot use the view because the target is already locked
 		$fileId = (int)$targetStorage->getCache()->getId($targetInternalPath);
 		if ($fileId === -1) {

lib/private/legacy/OC_Files.php

@@ -238,9 +238,6 @@ public static function get($dir, $files, $params = null) {
 			OC::$server->getLogger()->logException($ex);
 			$l = \OC::$server->getL10N('lib');
 			$hint = method_exists($ex, 'getHint') ? $ex->getHint() : '';
-			if ($event && $event->getErrorMessage() !== null) {
-				$hint .= ' ' . $event->getErrorMessage();
-			}
 			\OC_Template::printErrorPage($l->t('Cannot download file'), $hint, 200);
 		}
 	}