Fix crash when adding subtitles.

diff --git a/src/wx/closed_captions_dialog.cc b/src/wx/closed_captions_dialog.cc
index 8e007c38fcae29daf93438cd986c6f49b00c0d10..44e6b8da1d9162423bdafdfaab261935cfe9e3ff 100644 (file)
--- a/src/wx/closed_captions_dialog.cc
+++ b/src/wx/closed_captions_dialog.cc
@@ -148,10 +148,11 @@ ClosedCaptionsDialog::update (DCPTime time)
                _current = optional<TextRingBuffers::Data>();
        }
 
-       if (!_current) {
+       if (!_current && !_tracks.empty()) {
                /* We have no current one: get another */
                shared_ptr<Butler> butler = _butler.lock ();
                DCPOMATIC_ASSERT (butler);
+               DCPOMATIC_ASSERT (_track->GetSelection() >= 0);
                DCPOMATIC_ASSERT (_track->GetSelection() < int(_tracks.size()));
                DCPTextTrack track = _tracks[_track->GetSelection()];
                while (true) {