Fix logging in shutdown function

Author: bukka

sapi/fpm/fpm/fpm_stdio.c

@@ -106,9 +106,11 @@ int fpm_stdio_init_child(struct fpm_worker_pool_s *wp) /* {{{ */
 }
 /* }}} */
 
+#define FPM_STDIO_CMD_FLUSH "\0fscf"
+
 int fpm_stdio_flush_child() /* {{{ */
 {
-	return write(STDERR_FILENO, "\0", 1);
+	return write(STDERR_FILENO, FPM_STDIO_CMD_FLUSH, sizeof(FPM_STDIO_CMD_FLUSH));
 }
 /* }}} */
 
@@ -173,10 +175,20 @@ static void fpm_stdio_child_said(struct fpm_event_s *ev, short which, void *arg)
 				}
 			} else {
 				in_buf += res;
-				/* if buffer ends with \0, then the stream will be finished */
-				if (!buf[in_buf - 1]) {
+				/* check if buffer should be flushed */
+				if (!buf[in_buf - 1] && in_buf >= sizeof(FPM_STDIO_CMD_FLUSH) &&
+						!memcmp(buf + in_buf - sizeof(FPM_STDIO_CMD_FLUSH),
+							FPM_STDIO_CMD_FLUSH, sizeof(FPM_STDIO_CMD_FLUSH))) {
+					/* if buffer ends with flush cmd, then the stream will be finished */
+					finish_log_stream = 1;
+					in_buf -= sizeof(FPM_STDIO_CMD_FLUSH);
+				} else if (!buf[0] && in_buf > sizeof(FPM_STDIO_CMD_FLUSH) &&
+						!memcmp(buf, FPM_STDIO_CMD_FLUSH, sizeof(FPM_STDIO_CMD_FLUSH))) {
+					/* if buffer starts with flush cmd, then the stream will be finished */
 					finish_log_stream = 1;
-					in_buf--;
+					in_buf -= sizeof(FPM_STDIO_CMD_FLUSH);
+					/* move data behind the flush cmd */
+					memmove(buf, buf + sizeof(FPM_STDIO_CMD_FLUSH), in_buf);
 				}
 			}
 		}

sapi/fpm/tests/log-bm-in-shutdown-fn.phpt

@@ -0,0 +1,49 @@
+--TEST--
+FPM: Log message in shutdown function
+--SKIPIF--
+<?php include "skipif.inc"; ?>
+--FILE--
+<?php
+
+require_once "tester.inc";
+
+$cfg = <<<EOT
+[global]
+error_log = {{FILE:LOG}}
+log_limit = 1024
+log_buffering = yes
+[unconfined]
+listen = {{ADDR}}
+pm = dynamic
+pm.max_children = 5
+pm.start_servers = 1
+pm.min_spare_servers = 1
+pm.max_spare_servers = 3
+catch_workers_output = yes
+EOT;
+
+$code = <<<EOT
+<?php
+register_shutdown_function(function() {
+    error_log(str_repeat('e', 80));
+});
+EOT;
+
+$tester = new FPM\Tester($cfg, $code);
+$tester->start();
+$tester->expectLogStartNotices();
+$tester->request()->expectEmptyBody();
+$tester->terminate();
+$tester->expectFastCGIErrorMessage('e', 1050, 80);
+$tester->expectLogMessage('NOTICE: PHP message: ' . str_repeat('e', 80), 1050);
+$tester->close();
+
+?>
+Done
+--EXPECT--
+Done
+--CLEAN--
+<?php
+require_once "tester.inc";
+FPM\Tester::clean();
+?>