From 6ba9774460e35a1f8933c3192b39244ddec9ad55 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Mon, 1 Jul 2019 20:49:25 +0100
Subject: MemStream error handling and move support

---
 libadhocutil/memstream.cpp               | 41 +++++++++++++++++++++++++++++++-
 libadhocutil/memstream.h                 |  6 +++--
 libadhocutil/unittests/testMemStream.cpp | 13 ++++++++++
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/libadhocutil/memstream.cpp b/libadhocutil/memstream.cpp
index a4ce95e..ec4b1bb 100644
--- a/libadhocutil/memstream.cpp
+++ b/libadhocutil/memstream.cpp
@@ -1,5 +1,8 @@
 #include "memstream.h"
 #include <cstdlib>
+#include <cerrno>
+#include <cstring>
+#include <sys.h>
 
 namespace AdHoc {
 	MemStream::MemStream() :
@@ -7,13 +10,49 @@ namespace AdHoc {
 		len(0),
 		strm(open_memstream(&buf, &len))
 	{
+		if (!strm) {
+			// LCOV_EXCL_START no sensible way to make open_memstream fail
+			throw SystemException("open_memstream failed", strerror(errno), errno);
+			// LCOV_EXCL_STOP
+		}
+	}
+
+	MemStream::MemStream(MemStream && o) noexcept :
+		buf(o.buf),
+		len(o.len),
+		strm(o.strm)
+	{
+		o.buf = nullptr;
+		o.len = 0;
+		o.strm = nullptr;
 	}
 
 	MemStream::~MemStream()
 	{
-		fclose(strm);
+		if (strm) {
+			fclose(strm);
+		}
+		// NOLINTNEXTLINE(hicpp-no-malloc)
+		free(buf);
+	}
+
+	MemStream & MemStream::operator=(MemStream && o) noexcept
+	{
+		if (strm) {
+			fclose(strm);
+		}
 		// NOLINTNEXTLINE(hicpp-no-malloc)
 		free(buf);
+
+		buf = o.buf;
+		len = o.len;
+		strm = o.strm;
+
+		o.buf = nullptr;
+		o.len = 0;
+		o.strm = nullptr;
+
+		return *this;
 	}
 
 	MemStream::operator FILE * ()
diff --git a/libadhocutil/memstream.h b/libadhocutil/memstream.h
index 20b65fc..ba5f1fc 100644
--- a/libadhocutil/memstream.h
+++ b/libadhocutil/memstream.h
@@ -15,10 +15,12 @@ namespace AdHoc {
 			~MemStream();
 
 			MemStream(const MemStream &) = delete;
-			MemStream(MemStream &&) = delete;
+			/// Standard move constructor
+			MemStream(MemStream &&) noexcept;
 
 			void operator=(const MemStream &) = delete;
-			void operator=(MemStream &&) = delete;
+			/// Standard move assignment
+			MemStream & operator=(MemStream &&) noexcept;
 
 			/// Implicit conversion to use as FILE* for writes
 			operator FILE * ();
diff --git a/libadhocutil/unittests/testMemStream.cpp b/libadhocutil/unittests/testMemStream.cpp
index b244b5e..79100ee 100644
--- a/libadhocutil/unittests/testMemStream.cpp
+++ b/libadhocutil/unittests/testMemStream.cpp
@@ -32,3 +32,16 @@ BOOST_AUTO_TEST_CASE(simple)
 
 BOOST_AUTO_TEST_SUITE_END();
 
+BOOST_AUTO_TEST_CASE(move_construct)
+{
+	MemStream ms1;
+	MemStream ms2(std::move(ms1));
+}
+
+BOOST_AUTO_TEST_CASE(move_assign)
+{
+	MemStream ms1;
+	MemStream ms2;
+	ms2 = std::move(ms1);
+}
+
-- 
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