From 7f33db41594e740237030df05ab3d83f9531271f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Dzi=C4=99giel?= <rafostar.github@gmail.com>
Date: Wed, 11 May 2022 16:39:59 +0200
Subject: [PATCH] plugin: Fix possible buffer and v_info mismatch

---
 lib/gst/plugin/gstclapperimporter.c | 20 ++++++++++++--------
 lib/gst/plugin/gstclapperimporter.h |  1 +
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/lib/gst/plugin/gstclapperimporter.c b/lib/gst/plugin/gstclapperimporter.c
index 9ee4fa5f..035b0e44 100644
--- a/lib/gst/plugin/gstclapperimporter.c
+++ b/lib/gst/plugin/gstclapperimporter.c
@@ -119,6 +119,8 @@ gst_clapper_importer_finalize (GObject *object)
 
   GST_TRACE ("Finalize");
 
+  gst_clear_caps (&self->pending_caps);
+
   gst_clear_buffer (&self->pending_buffer);
   gst_clear_buffer (&self->buffer);
 
@@ -320,7 +322,7 @@ gst_clapper_importer_set_caps (GstClapperImporter *self, GstCaps *caps)
   GstClapperImporterClass *importer_class = GST_CLAPPER_IMPORTER_GET_CLASS (self);
 
   GST_OBJECT_LOCK (self);
-  self->has_pending_v_info = gst_video_info_from_caps (&self->pending_v_info, caps);
+  gst_caps_replace (&self->pending_caps, caps);
   GST_OBJECT_UNLOCK (self);
 
   if (importer_class->set_caps)
@@ -330,10 +332,14 @@ gst_clapper_importer_set_caps (GstClapperImporter *self, GstCaps *caps)
 void
 gst_clapper_importer_set_buffer (GstClapperImporter *self, GstBuffer *buffer)
 {
-  /* Both overlays and pending buffer must be
-   * set within a single importer locking */
   GST_OBJECT_LOCK (self);
 
+  /* Pending v_info, buffer and overlays must be
+   * set within a single importer locking */
+  if (self->pending_caps) {
+    self->has_pending_v_info = gst_video_info_from_caps (&self->pending_v_info, self->pending_caps);
+    gst_clear_caps (&self->pending_caps);
+  }
   gst_buffer_replace (&self->pending_buffer, buffer);
   gst_clapper_importer_prepare_overlays_locked (self);
 
@@ -380,15 +386,13 @@ gst_clapper_importer_snapshot (GstClapperImporter *self, GdkSnapshot *snapshot,
    * lock ourselves to make sure everything matches */
   GST_OBJECT_LOCK (self);
 
-  buffer_changed = gst_buffer_replace (&self->buffer, self->pending_buffer);
-
-  /* Only replace v_info when buffer changed, this way
-   * we still use old (correct) v_info when resizing */
-  if (buffer_changed && self->has_pending_v_info) {
+  if (self->has_pending_v_info) {
     self->v_info = self->pending_v_info;
     self->has_pending_v_info = FALSE;
   }
 
+  buffer_changed = gst_buffer_replace (&self->buffer, self->pending_buffer);
+
   /* Ref overlays associated with current buffer */
   for (i = 0; i < self->pending_overlays->len; i++) {
     GstClapperGdkOverlay *overlay = g_ptr_array_index (self->pending_overlays, i);
diff --git a/lib/gst/plugin/gstclapperimporter.h b/lib/gst/plugin/gstclapperimporter.h
index 6477f441..1f797de7 100644
--- a/lib/gst/plugin/gstclapperimporter.h
+++ b/lib/gst/plugin/gstclapperimporter.h
@@ -49,6 +49,7 @@ struct _GstClapperImporter
 {
   GstObject parent;
 
+  GstCaps *pending_caps;
   GstBuffer *pending_buffer, *buffer;
   GPtrArray *pending_overlays, *overlays;
   GstVideoInfo pending_v_info, v_info;