[mutter/wip/carlosg/incr-is-fubar: 22/27] x11: Only send SelectionNotify on first INCR chunk

[Carlos Garnacho <carlosg src gnome org>]

commit 485ee3de01371aa1a635d57f43c6a4bd149c7a0e
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Apr 11 17:05:24 2020 +0200

    x11: Only send SelectionNotify on first INCR chunk
    
    This should only be sent if the selection can be sent at once, or
    if we are right about to notify on the first chunk of an INCR
    transfer.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198

 src/x11/meta-x11-selection-output-stream.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/src/x11/meta-x11-selection-output-stream.c b/src/x11/meta-x11-selection-output-stream.c
index 7ae1e1acc..f7c27cc09 100644
--- a/src/x11/meta-x11-selection-output-stream.c
+++ b/src/x11/meta-x11-selection-output-stream.c
@@ -199,6 +199,7 @@ meta_x11_selection_output_stream_perform_flush (MetaX11SelectionOutputStream *st
     meta_x11_selection_output_stream_get_instance_private (stream);
   Display *xdisplay;
   size_t element_size, n_elements;
+  gboolean first_chunk = FALSE;
   int error_code;
 
   g_assert (!priv->delete_pending);
@@ -213,6 +214,9 @@ meta_x11_selection_output_stream_perform_flush (MetaX11SelectionOutputStream *st
   element_size = get_element_size (priv->format);
   n_elements = priv->data->len / element_size;
 
+  if (!priv->incr)
+    first_chunk = TRUE;
+
   if (!g_output_stream_is_closing (G_OUTPUT_STREAM (stream)))
     {
       XWindowAttributes attrs;
@@ -248,7 +252,8 @@ meta_x11_selection_output_stream_perform_flush (MetaX11SelectionOutputStream *st
       g_byte_array_remove_range (priv->data, 0, n_elements * element_size);
     }
 
-  meta_x11_selection_output_stream_notify_selection (stream);
+  if (first_chunk)
+    meta_x11_selection_output_stream_notify_selection (stream);
 
   priv->delete_pending = TRUE;
   g_cond_broadcast (&priv->cond);