fix: handle client disconnect properly with ignore_user_abort true

lib/Sapi.php

@@ -113,6 +113,12 @@ public static function sendResponse(ResponseInterface $response): void
                     if ($copied <= 0) {
                         break;
                     }
+                    // Abort on client disconnect.
+                    // With ignore_user_abort(true), the script is not aborted on client disconnect.
+                    // To avoid reading the entire stream and dismissing the data afterward, check between the chunks if the client is still there.
+                    if (1 === ignore_user_abort() && 1 === connection_aborted()) {
+                        break;
+                    }
                     $left -= $copied;
                 }
             } else {

tests/HTTP/SapiTest.php

@@ -300,4 +300,35 @@ public function testSendWorksWithCallbackAsBody(): void
 
         self::assertEquals('foo', $result);
     }
+
+    public function testSendConnectionAborted(): void
+    {
+        $baseUrl = getenv('BASEURL');
+        if (!$baseUrl) {
+            $this->markTestSkipped('Set an environment value BASEURL to continue');
+        }
+
+        $url = rtrim($baseUrl, '/').'/connection_aborted.php';
+        $chunk_size = 4 * 1024 * 1024;
+        $fetch_size = 6 * 1024 * 1024;
+
+        $stream = fopen($url, 'r');
+        $size = 0;
+
+        while ($size <= $fetch_size) {
+            $temp = fread($stream, 8192);
+            if (false === $temp) {
+                break;
+            }
+            $size += strlen($temp);
+        }
+
+        fclose($stream);
+
+        sleep(5);
+
+        $bytes_read = file_get_contents(sys_get_temp_dir().'/dummy_stream_read_counter');
+        $this->assertEquals($chunk_size * 2, $bytes_read);
+        $this->assertGreaterThanOrEqual($fetch_size, $bytes_read);
+    }
 }

tests/www/connection_aborted.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+use Sabre\HTTP;
+
+include '../bootstrap.php';
+
+class DummyStream
+{
+    private int $position;
+
+    public function stream_open(string $path, string $mode, int $options, ?string &$opened_path): bool
+    {
+        $this->position = 0;
+
+        return true;
+    }
+
+    public function stream_read(int $count): string
+    {
+        $this->position += $count;
+
+        return random_bytes($count);
+    }
+
+    public function stream_tell(): int
+    {
+        return $this->position;
+    }
+
+    public function stream_eof(): bool
+    {
+        return $this->position > 25 * 1024 * 1024;
+    }
+
+    public function stream_close(): void
+    {
+        file_put_contents(sys_get_temp_dir().'/dummy_stream_read_counter', $this->position);
+    }
+}
+
+/*
+ * The DummyStream wrapper has two functions:
+ * - Provide dummy data.
+ * - Count how many bytes have been read.
+ */
+stream_wrapper_register('dummy', DummyStream::class);
+
+/*
+ * Overwrite default connection handling.
+ * The default behaviour is however for your script to be aborted when the remote client disconnects.
+ *
+ * Nextcloud/ownCloud set ignore_user_abort(true) on purpose to work around
+ * some edge cases where the default behavior would end a script too early.
+ *
+ * https://github.com/owncloud/core/issues/22370
+ * https://github.com/owncloud/core/pull/26775
+ */
+ignore_user_abort(true);
+
+$body = fopen('dummy://hello', 'r');
+
+$response = new HTTP\Response();
+$response->setStatus(200);
+$response->addHeader('Content-Length', 25 * 1024 * 1024);
+$response->setBody($body);
+
+HTTP\Sapi::sendResponse($response);