cbs_h2645: Ensure that non-refcounted parameter sets are fully copied

Only copying the main structure is not necessarily sufficient - there
could be references to substructures.

libavcodec/cbs_h2645.c

@@ -720,18 +720,20 @@ static int cbs_h26 ## h26n ## _replace_ ## ps_var(CodedBitstreamContext *ctx, \
     CodedBitstreamH26 ## h26n ## Context *priv = ctx->priv_data; \
     H26 ## h26n ## Raw ## ps_name *ps_var = unit->content; \
     unsigned int id = ps_var->id_element; \
+    int err; \
     if (id >= FF_ARRAY_ELEMS(priv->ps_var)) { \
         av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid " #ps_name \
                " id : %d.\n", id); \
         return AVERROR_INVALIDDATA; \
     } \
+    err = ff_cbs_make_unit_refcounted(ctx, unit); \
+    if (err < 0) \
+        return err; \
     if (priv->ps_var[id] == priv->active_ ## ps_var) \
         priv->active_ ## ps_var = NULL ; \
     av_buffer_unref(&priv->ps_var ## _ref[id]); \
-    if (unit->content_ref) \
-        priv->ps_var ## _ref[id] = av_buffer_ref(unit->content_ref); \
-    else \
-        priv->ps_var ## _ref[id] = av_buffer_alloc(sizeof(*ps_var)); \
+    av_assert0(unit->content_ref); \
+    priv->ps_var ## _ref[id] = av_buffer_ref(unit->content_ref); \
     if (!priv->ps_var ## _ref[id]) \
         return AVERROR(ENOMEM); \
     priv->ps_var[id] = (H26 ## h26n ## Raw ## ps_name *)priv->ps_var ## _ref[id]->data; \