<ContentVersion> is optional in Interop so we can't assume it's there.

3 files changed, 11 insertions, 6 deletions

diff --git a/src/cpl.cc b/src/cpl.cc
index ead592fd..2768e797 100644
--- a/src/cpl.cc
+++ b/src/cpl.cc
@@ -654,10 +654,13 @@ CPL::set_content_versions (vector<ContentVersion> v)
 }
 
 
-ContentVersion
+optional<ContentVersion>
 CPL::content_version () const
 {
-	DCP_ASSERT (!_content_versions.empty());
+	if (_content_versions.empty()) {
+		return optional<ContentVersion>();
+	}
+
 	return _content_versions[0];
 }
 
diff --git a/src/cpl.h b/src/cpl.h
index 72366ee3..c1f505df 100644
--- a/src/cpl.h
+++ b/src/cpl.h
@@ -140,7 +140,7 @@ public:
 		return _content_kind;
 	}
 
-	ContentVersion content_version () const;
+	boost::optional<ContentVersion> content_version () const;
 
 	std::vector<ContentVersion> content_versions () const {
 		return _content_versions;
diff --git a/test/write_subtitle_test.cc b/test/write_subtitle_test.cc
index b7d8119a..4bdc6e9d 100644
--- a/test/write_subtitle_test.cc
+++ b/test/write_subtitle_test.cc
@@ -46,6 +46,7 @@
 
 using std::list;
 using std::string;
+using boost::optional;
 using boost::shared_ptr;
 
 /** Test dcp::order::Font::take_intersection */
@@ -372,9 +373,10 @@ BOOST_AUTO_TEST_CASE (write_interop_subtitle_test3)
 	cpl->set_creator (creator);
 	cpl->set_issue_date (issue_date);
 	cpl->set_annotation_text (annotation_text);
-	dcp::ContentVersion cv = cpl->content_version();
-	cv.label_text = "foo";
-	cpl->set_content_version (cv);
+	optional<dcp::ContentVersion> cv = cpl->content_version();
+	BOOST_REQUIRE (cv);
+	cv->label_text = "foo";
+	cpl->set_content_version (*cv);
 
 	dcp::DCP dcp ("build/test/write_interop_subtitle_test3");
 	dcp.add (cpl);