Fix crash on DCP content with no subs.

diff --git a/src/lib/dcp_content.cc b/src/lib/dcp_content.cc
index 7a2d350de6b85e574953c0262d2cf55025b05cdc..b77c22714a2a00c48b4509343bae7b86c03cedc7 100644 (file)
--- a/src/lib/dcp_content.cc
+++ b/src/lib/dcp_content.cc
@@ -199,8 +199,11 @@ string
 DCPContent::identifier () const
 {
        SafeStringStream s;
-       s << Content::identifier() << "_" << video->identifier() << "_" << subtitle->identifier () << " "
-         << (_reference_video ? "1" : "0")
+       s << Content::identifier() << "_" << video->identifier() << "_";
+       if (subtitle) {
+               s << subtitle->identifier () << " ";
+       }
+       s << (_reference_video ? "1" : "0")
          << (_reference_subtitle ? "1" : "0");
        return s.str ();
 }