[mutter] wayland-dma-buf: Don't send modifiers to old clients

[Jonas Ådahl <jadahl src gnome org>]

commit 32917f1922c3a727f747477caad1f9611582fe59
Author: Daniel Stone <daniels collabora com>
Date:   Mon Oct 2 16:46:17 2017 +0100

    wayland-dma-buf: Don't send modifiers to old clients
    
    The modifier event was only added in v3 of the client; sending it to
    older clients (e.g. GStreamer waylandsink) causes them to disconnect
    immediately.
    
    Send the older 'format' event to all clients, and only send the newer
    'modifier' event to resource versions 3 or above.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=788558

 src/wayland/meta-wayland-dma-buf.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)
---
diff --git a/src/wayland/meta-wayland-dma-buf.c b/src/wayland/meta-wayland-dma-buf.c
index e5d2f7c..76b8aa2 100644
--- a/src/wayland/meta-wayland-dma-buf.c
+++ b/src/wayland/meta-wayland-dma-buf.c
@@ -473,12 +473,19 @@ send_modifiers (struct wl_resource *resource,
   gboolean ret;
   int i;
 
+  zwp_linux_dmabuf_v1_send_format (resource, format);
+
+  /* The modifier event was only added in v3; v1 and v2 only have the format
+   * event. */
+  if (wl_resource_get_version (resource) < ZWP_LINUX_DMABUF_V1_MODIFIER_SINCE_VERSION)
+    return;
+
   /* First query the number of available modifiers, then allocate an array,
    * then fill the array. */
   ret = meta_egl_query_dma_buf_modifiers (egl, egl_display, format, 0, NULL,
                                           NULL, &num_modifiers, NULL);
   if (!ret || num_modifiers == 0)
-     return;
+    return;
 
   modifiers = g_new0 (uint64_t, num_modifiers);
   ret = meta_egl_query_dma_buf_modifiers (egl, egl_display, format,