diff --git a/dives/test47+48.xml b/dives/test47+48.xml
new file mode 100644
index 000000000..aa4c129c0
--- /dev/null
+++ b/dives/test47+48.xml
@@ -0,0 +1,22 @@
+<divelog program='subsurface' version='3'>
+<settings>
+</settings>
+<divesites>
+<site uuid='15ae02d0' name='Test dive'>
+</site>
+</divesites>
+<dives>
+<dive number='1' tags='test' divesiteid='15ae02d0' date='2015-10-01' time='08:00:25' duration='46:00 min'>
+  <cylinder size='11.1 l' workpressure='207.0 bar' description='unknown' />
+  <divecomputer model='do not care' date='2015-10-05' time='08:45:25'>
+  <depth max='13.716 m' mean='10.595 m' />
+  <sample time='0:00 min' depth='0.0 m' />
+  <sample time='0:36 min' depth='13.716 m' />
+  <sample time='20:00 min' depth='13.716 m' />
+  <sample time='42:00 min' depth='4.572 m' />
+  <sample time='45:00 min' depth='4.572 m' />
+  <sample time='46:00 min' depth='0.0 m' />
+  </divecomputer>
+</dive>
+</dives>
+</divelog>
diff --git a/dives/test48.xml b/dives/test48.xml
new file mode 100644
index 000000000..421325c4b
--- /dev/null
+++ b/dives/test48.xml
@@ -0,0 +1,13 @@
+<divelog program='subsurface' version='3'>
+<divesites>
+<site uuid='15ae02d1'>
+</site>
+</divesites>
+<dives>
+<dive number='1' tags='test' divesiteid='15ae02d1' date='2015-10-01' time='08:00:25' duration='46:00 min'>
+  <divecomputer date='2015-10-05' time='08:45:25'>
+  <depth max='13.716 m' mean='10.595 m' />
+  </divecomputer>
+</dive>
+</dives>
+</divelog>
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 5106588d0..1aab4ab1c 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -21,6 +21,7 @@ TEST(TestRenumber testrenumber.cpp)
 TEST(TestGitStorage testgitstorage.cpp)
 TEST(TestPreferences testpreferences.cpp)
 TEST(TestPicture testpicture.cpp)
+TEST(TestMerge testmerge.cpp)
 
 
 add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND}
@@ -35,4 +36,5 @@ add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND}
 	TestPreferences
 	TestRenumber
 	TestPicture
+	TestMerge
 )
diff --git a/tests/testmerge.cpp b/tests/testmerge.cpp
new file mode 100644
index 000000000..05c88a88e
--- /dev/null
+++ b/tests/testmerge.cpp
@@ -0,0 +1,61 @@
+#include "testmerge.h"
+#include "core/dive.h"
+#include "core/file.h"
+#include "core/divelist.h"
+#include <QTextStream>
+
+void TestMerge::initTestCase()
+{
+	/* we need to manually tell that the resource exists, because we are using it as library. */
+	Q_INIT_RESOURCE(subsurface);
+}
+
+void TestMerge::testMergeEmpty()
+{
+	/*
+	 * check that we correctly merge mixed cylinder dives
+	 */
+	QCOMPARE(parse_file(SUBSURFACE_SOURCE "/dives/test47.xml"), 0);
+	process_dives(true, false);
+	QCOMPARE(parse_file(SUBSURFACE_SOURCE "/dives/test48.xml"), 0);
+	process_dives(true, false);
+	QCOMPARE(save_dives("./testmerge47+48.ssrf"), 0);
+	QFile org(SUBSURFACE_SOURCE "/dives/test47+48.xml");
+	org.open(QFile::ReadOnly);
+	QFile out("./testmerge47+48.ssrf");
+	out.open(QFile::ReadOnly);
+	QTextStream orgS(&org);
+	QTextStream outS(&out);
+	QStringList readin = orgS.readAll().split("\n");
+	QStringList written = outS.readAll().split("\n");
+	while(readin.size() && written.size()){
+		QCOMPARE(readin.takeFirst(), written.takeFirst());
+	}
+	clear_dive_file_data();
+}
+
+void TestMerge::testMergeBackwards()
+{
+	/*
+	 * check that we correctly merge mixed cylinder dives
+	 */
+	QCOMPARE(parse_file(SUBSURFACE_SOURCE "/dives/test48.xml"), 0);
+	process_dives(true, false);
+	QCOMPARE(parse_file(SUBSURFACE_SOURCE "/dives/test47.xml"), 0);
+	process_dives(true, false);
+	QCOMPARE(save_dives("./testmerge47+48.ssrf"), 0);
+	QFile org(SUBSURFACE_SOURCE "/dives/test47+48.xml");
+	org.open(QFile::ReadOnly);
+	QFile out("./testmerge47+48.ssrf");
+	out.open(QFile::ReadOnly);
+	QTextStream orgS(&org);
+	QTextStream outS(&out);
+	QStringList readin = orgS.readAll().split("\n");
+	QStringList written = outS.readAll().split("\n");
+	while(readin.size() && written.size()){
+		QCOMPARE(readin.takeFirst(), written.takeFirst());
+	}
+	clear_dive_file_data();
+}
+
+QTEST_GUILESS_MAIN(TestMerge)
diff --git a/tests/testmerge.h b/tests/testmerge.h
new file mode 100644
index 000000000..771afc4db
--- /dev/null
+++ b/tests/testmerge.h
@@ -0,0 +1,14 @@
+#ifndef TESTMERGE_H
+#define TESTMERGE_H
+
+#include <QtTest>
+
+class TestMerge : public QObject{
+	Q_OBJECT
+private slots:
+	void initTestCase();
+	void testMergeEmpty();
+	void testMergeBackwards();
+};
+
+#endif