From d0a707b3d0c247d6bbf63fdfefc79d5ce0aea717 Mon Sep 17 00:00:00 2001
From: Tobias Hunger <tobias.hunger@qt.io>
Date: Mon, 14 Nov 2016 15:38:05 +0100
Subject: [PATCH] server-mode: Prevent possible crash when watching directories

The `filename` passed by libuv may be `nullptr`, so handle that
explicitly.

Fixes: #16422
---
 Source/cmFileMonitor.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/cmFileMonitor.cxx b/Source/cmFileMonitor.cxx
index 41ec8b415..ea37683bb 100644
--- a/Source/cmFileMonitor.cxx
+++ b/Source/cmFileMonitor.cxx
@@ -288,7 +288,7 @@ void on_directory_change(uv_fs_event_t* handle, const char* filename,
 {
   const cmIBaseWatcher* const watcher =
     static_cast<const cmIBaseWatcher*>(handle->data);
-  const std::string pathSegment(filename);
+  const std::string pathSegment(filename ? filename : "");
   watcher->Trigger(pathSegment, events, status);
 }