[gnome-builder/gnome-builder-3-26] spellcheck: be defensive against race conditions

[Christian Hergert <chergert src gnome org>]

commit d2e23d53ce1b3e33811c160d27eb6a31069e7a81
Author: Christian Hergert <chergert redhat com>
Date:   Mon Oct 9 13:30:48 2017 -0700

    spellcheck: be defensive against race conditions
    
    If we are in a situation where the buffer is already in the dispose
    phase, we can't do much about it here. Our view should be cleaned up
    shortly. Just short circuit and wait for unload.

 plugins/spellcheck/gbp-spell-editor-view-addin.c |   19 +++++++++++++++----
 1 files changed, 15 insertions(+), 4 deletions(-)
---
diff --git a/plugins/spellcheck/gbp-spell-editor-view-addin.c 
b/plugins/spellcheck/gbp-spell-editor-view-addin.c
index a44282d..2b48afa 100644
--- a/plugins/spellcheck/gbp-spell-editor-view-addin.c
+++ b/plugins/spellcheck/gbp-spell-editor-view-addin.c
@@ -129,8 +129,16 @@ gbp_spell_editor_view_addin_load (IdeEditorViewAddin *addin,
   g_assert (IDE_IS_BUFFER (buffer));
 
   buffer_addin = ide_buffer_addin_find_by_module_name (buffer, "spellcheck-plugin");
-  g_assert (buffer_addin != NULL);
-  g_assert (GBP_IS_SPELL_BUFFER_ADDIN (buffer_addin));
+
+  if (!GBP_IS_SPELL_BUFFER_ADDIN (buffer_addin))
+    {
+      /* We might find ourselves in a race here and the buffer
+       * addins are already in destruction. Therefore, silently
+       * fail any further setup.
+       */
+      g_warning ("Failed to locate buffer addin, spellcheck disabled");
+      return;
+    }
 
   wrapper = gspell_text_view_get_from_gtk_text_view (GTK_TEXT_VIEW (source_view));
   g_assert (wrapper != NULL);
@@ -175,8 +183,11 @@ gbp_spell_editor_view_addin_unload (IdeEditorViewAddin *addin,
 
   gtk_widget_insert_action_group (GTK_WIDGET (view), "spellcheck", NULL);
 
-  dzl_binding_group_set_source (self->buffer_addin_bindings, NULL);
-  g_clear_object (&self->buffer_addin_bindings);
+  if (self->buffer_addin_bindings != NULL)
+    {
+      dzl_binding_group_set_source (self->buffer_addin_bindings, NULL);
+      g_clear_object (&self->buffer_addin_bindings);
+    }
 
   g_clear_object (&self->navigator);