viewer: re-queue video renderer even when beyond the length

Ensures video renderer always renders where the playhead is.

app/render/backend/videorenderbackend.cpp

@@ -165,7 +165,7 @@ VideoRenderFrameCache *VideoRenderBackend::frame_cache()
 
 QString VideoRenderBackend::GetCachedFrame(const rational &time)
 {
-  last_time_requested_ = time;
+  UpdateLastRequestedTime(time);
 
   if (viewer_node() == nullptr) {
     // Nothing is connected - nothing to show or render
@@ -182,8 +182,6 @@ QString VideoRenderBackend::GetCachedFrame(const rational &time)
     return nullptr;
   }
 
-  Requeue();
-
   // Find frame in map
   QByteArray frame_hash = frame_cache_.TimeToHash(time);
 
@@ -196,6 +194,13 @@ QString VideoRenderBackend::GetCachedFrame(const rational &time)
   return QString();
 }
 
+void VideoRenderBackend::UpdateLastRequestedTime(const rational &time)
+{
+  last_time_requested_ = time;
+
+  Requeue();
+}
+
 NodeInput *VideoRenderBackend::GetDependentInput()
 {
   return viewer_node()->texture_input();

app/render/backend/videorenderbackend.h

@@ -66,6 +66,8 @@ public:
 
   QString GetCachedFrame(const rational& time);
 
+  void UpdateLastRequestedTime(const rational& time);
+
   VideoRenderFrameCache* frame_cache();
 
   const VideoRenderingParams& params() const;

app/widget/viewer/viewer.cpp

@@ -320,6 +320,7 @@ void ViewerWidget::UpdateTextureFromNode(const rational& time)
 {
   if (!GetConnectedNode() || time >= GetConnectedNode()->Length()) {
     main_gl_widget()->SetImage(QString());
+    video_renderer_->UpdateLastRequestedTime(time);
   } else {
     QString frame_fn = video_renderer_->GetCachedFrame(time);