[nautilus/1535-nautilus-crashes-when-dragging-from-archive-manager] window-slot-dnd: Fix data retrieval failure path

[António Fernandes <antoniof src gnome org>]

commit 67a0c763b64a7d5c0adacfa84e875ff1060a0ed3
Author: António Fernandes <antoniof gnome org>
Date:   Fri Jul 16 22:47:40 2021 +0100

    window-slot-dnd: Fix data retrieval failure path
    
    When data retrieval fails, ::drag-data-received is emitted with a
    selection of negative length.
    
    We have been treating this case as invalid data, but we never actually
    call gdk_drag_finish() which is mandatory after a drop.
    
    Instead, reset drag_info->have_data to FALSE in this case, and let
    slot_proxy_handle_drop() handle the rest.

 src/nautilus-window-slot-dnd.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/src/nautilus-window-slot-dnd.c b/src/nautilus-window-slot-dnd.c
index 9509d2c97..ec0134e46 100644
--- a/src/nautilus-window-slot-dnd.c
+++ b/src/nautilus-window-slot-dnd.c
@@ -472,17 +472,21 @@ slot_proxy_drag_data_received (GtkWidget        *widget,
     drag_info = user_data;
 
     g_assert (!drag_info->have_data);
-
-    drag_info->have_data = TRUE;
-    drag_info->info = info;
     drag_info->waiting_for_data = FALSE;
 
     if (gtk_selection_data_get_length (data) < 0)
     {
-        drag_info->have_valid_data = FALSE;
+        /* Data retrieval failed. */
+        if (drag_info->drop_occurred)
+        {
+            gtk_drag_finish (context, FALSE, FALSE, time);
+        }
         return;
     }
 
+    drag_info->have_data = TRUE;
+    drag_info->info = info;
+
     if (info == NAUTILUS_ICON_DND_GNOME_ICON_LIST)
     {
         drag_info->data.selection_list = nautilus_drag_build_selection_list (data);