[gthumb] video viewer: correctly update the has_audio/has_video flags

[Paolo Bacchilega <paobac src gnome org>]

commit 1f6cec793543a98ec4417c0eb2c74a747bd0a909
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sun Feb 16 11:43:43 2020 +0100

    video viewer: correctly update the has_audio/has_video flags

 extensions/gstreamer_tools/gth-media-viewer-page.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/extensions/gstreamer_tools/gth-media-viewer-page.c 
b/extensions/gstreamer_tools/gth-media-viewer-page.c
index e3f9e97d..0db3bb55 100644
--- a/extensions/gstreamer_tools/gth-media-viewer-page.c
+++ b/extensions/gstreamer_tools/gth-media-viewer-page.c
@@ -680,6 +680,9 @@ update_stream_info (GthMediaViewerPage *self)
                      "video-sink", &video_sink,
                      NULL);
 
+       self->priv->has_audio = FALSE;
+       self->priv->has_video = FALSE;
+
        if (audio_sink != NULL) {
                audio_pad = gst_element_get_static_pad (GST_ELEMENT (audio_sink), "sink");
                if (audio_pad != NULL) {