From 359542d53ec142514da8a606ada8d9efd13b9678 Mon Sep 17 00:00:00 2001
From: Tim Blechmann <tim@klingt.org>
Date: Sat, 10 Sep 2022 12:18:19 +0800
Subject: [PATCH] FileStream: enable automatic flushing

when a test executable is killed by a signal (e.g. when executed by
ctest with timeout), the reporter files are not flushed. this can lead
to incomplete (or empty) report files.
to avoid this we enable automatic flushing via `std::unitbuf`

compare #663
---
 src/catch2/internal/catch_istream.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/catch2/internal/catch_istream.cpp b/src/catch2/internal/catch_istream.cpp
index 4cd35058..6d1fa94b 100644
--- a/src/catch2/internal/catch_istream.cpp
+++ b/src/catch2/internal/catch_istream.cpp
@@ -78,6 +78,7 @@ namespace Detail {
             FileStream( std::string const& filename ) {
                 m_ofs.open( filename.c_str() );
                 CATCH_ENFORCE( !m_ofs.fail(), "Unable to open file: '" << filename << '\'' );
+                m_ofs << std::unitbuf;
             }
             ~FileStream() override = default;
         public: // IStream