From 6cc748cce9bb7cb47a4098cdc251c554d9f99b6b Mon Sep 17 00:00:00 2001
From: Robert Mader <robert.mader@posteo.de>
Date: Wed, 29 Jan 2020 00:11:18 +0100
Subject: [PATCH] wayland/data-device: Cancel drag source when the drag
 finished unsuccessfully

When a drag was performed but did not finish successfully, e.g. because no
mimetype was accepted, we need to send the source cancel event so clients
know they can destroy the drag source (since version 3).

Fixes https://gitlab.gnome.org/GNOME/mutter/issues/740

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1031
---
 src/wayland/meta-wayland-data-device.c | 30 ++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/wayland/meta-wayland-data-device.c b/src/wayland/meta-wayland-data-device.c
index 7e0a254b4..9a4ba9a92 100644
--- a/src/wayland/meta-wayland-data-device.c
+++ b/src/wayland/meta-wayland-data-device.c
@@ -75,6 +75,7 @@ typedef struct _MetaWaylandDataSourcePrivate
   MetaWaylandSeat *seat;
   guint actions_set : 1;
   guint in_ask : 1;
+  guint drop_performed : 1;
 } MetaWaylandDataSourcePrivate;
 
 typedef struct _MetaWaylandDataSourcePrimary
@@ -95,6 +96,9 @@ meta_wayland_data_source_new (struct wl_resource *resource);
 static MetaWaylandDataSource *
 meta_wayland_data_source_primary_new (struct wl_resource *resource);
 
+static void
+meta_wayland_source_cancel (MetaWaylandDataSource *source);
+
 static void
 drag_grab_data_source_destroyed (gpointer data, GObject *where_the_object_was);
 
@@ -363,6 +367,15 @@ meta_wayland_data_source_set_user_action (MetaWaylandDataSource *source,
     data_offer_update_action (offer);
 }
 
+static gboolean
+meta_wayland_data_source_get_drop_performed (MetaWaylandDataSource *source)
+{
+  MetaWaylandDataSourcePrivate *priv =
+    meta_wayland_data_source_get_instance_private (source);
+
+  return priv->drop_performed;
+}
+
 static void
 data_offer_accept (struct wl_client *client,
                    struct wl_resource *resource,
@@ -577,11 +590,17 @@ destroy_data_offer (struct wl_resource *resource)
 
       if (offer == meta_wayland_data_source_get_current_offer (offer->source))
         {
-          if (seat->data_device.dnd_data_source == offer->source &&
-              wl_resource_get_version (offer->resource) <
-              WL_DATA_OFFER_ACTION_SINCE_VERSION)
+          if (seat->data_device.dnd_data_source == offer->source)
             {
-              meta_wayland_data_source_notify_finish (offer->source);
+              if (wl_resource_get_version (offer->resource) <
+                  WL_DATA_OFFER_ACTION_SINCE_VERSION)
+                meta_wayland_data_source_notify_finish (offer->source);
+              else if (meta_wayland_data_source_get_drop_performed (offer->source) &&
+                       meta_wayland_data_source_get_resource(offer->source) &&
+                       wl_resource_get_version(
+                       meta_wayland_data_source_get_resource(offer->source)) >=
+                       WL_DATA_SOURCE_DND_FINISHED_SINCE_VERSION)
+                meta_wayland_source_cancel (offer->source);
             }
           else
             {
@@ -1390,6 +1409,8 @@ meta_wayland_source_drop_performed (MetaWaylandDataSource *source)
   MetaWaylandDataSourcePrivate *priv =
     meta_wayland_data_source_get_instance_private (source);
 
+  priv->drop_performed = TRUE;
+
   if (wl_resource_get_version (priv->resource) >=
       WL_DATA_SOURCE_DND_DROP_PERFORMED_SINCE_VERSION)
     wl_data_source_send_dnd_drop_performed (priv->resource);
@@ -1440,6 +1461,7 @@ meta_wayland_data_source_init (MetaWaylandDataSource *source)
 
   wl_array_init (&priv->mime_types);
   priv->current_dnd_action = -1;
+  priv->drop_performed = FALSE;
 }
 
 static void