vo_opengl: cache frames only in display-sync mode

vo_frame.num_vsyncs can be != 1 in some cases in normal sync mode too.
This is not a very exact fix, but in exchange it's robust. (These
vo_frame flags are way too tricky in combination with redrawing and
such.)

1 files changed, 3 insertions, 1 deletions

diff --git a/video/out/opengl/video.c b/video/out/opengl/video.c
index 60d987a31b..00c7663e91 100644
--- a/video/out/opengl/video.c
+++ b/video/out/opengl/video.c
@@ -1926,7 +1926,9 @@ void gl_video_render_frame(struct gl_video *p, struct vo_frame *frame, int fbo)
                 gl_video_upload_image(p, frame->current);
                 pass_render_frame(p);
 
-                if (frame->num_vsyncs == 1 || p->opts.dumb_mode) {
+                if (frame->num_vsyncs == 1 || !frame->display_synced ||
+                    p->opts.dumb_mode)
+                {
                     // Disable output_fbo_valid to signal that this frame
                     // does not require any redraws from the FBO.
                     pass_draw_to_screen(p, fbo);