From 0da3002815ed985746ba28332890a97687e40a51 Mon Sep 17 00:00:00 2001
From: mandreyel <mandreyel@protonmail.com>
Date: Wed, 7 Nov 2018 11:08:34 +0100
Subject: [PATCH] Fix missing error code in conditional_sync

---
 include/mio/detail/mmap.ipp | 2 +-
 include/mio/mmap.hpp        | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/mio/detail/mmap.ipp b/include/mio/detail/mmap.ipp
index 1618ef1..a813fc3 100644
--- a/include/mio/detail/mmap.ipp
+++ b/include/mio/detail/mmap.ipp
@@ -334,7 +334,7 @@ void basic_mmap<AccessMode, ByteT>::sync(std::error_code& error)
         return;
     }
 
-    if(data() != nullptr)
+    if(data())
     {
 #ifdef _WIN32
         if(::FlushViewOfFile(get_mapping_start(), mapped_length_) == 0
diff --git a/include/mio/mmap.hpp b/include/mio/mmap.hpp
index ed4af12..fd18d2b 100644
--- a/include/mio/mmap.hpp
+++ b/include/mio/mmap.hpp
@@ -372,7 +372,14 @@ private:
      */
     template<access_mode A = AccessMode,
             typename = typename std::enable_if<A == access_mode::write>::type>
-    void conditional_sync() { sync(); }
+    void conditional_sync()
+    {
+        // This is invoked from the destructor, so not much we can do about
+        // failures here.
+        std::error_code ec;
+        sync(ec);
+    }
+
     template<access_mode A = AccessMode>
     typename std::enable_if<A == access_mode::read, void>::type conditional_sync() {}
 };