[gnome-builder] html-preview: fix leak of IdeEditorView

[Christian Hergert <chergert src gnome org>]

commit 812d99d8df0a04ee90bea6855a959d438ec515f7
Author: Christian Hergert <chergert redhat com>
Date:   Wed Sep 20 02:44:00 2017 -0700

    html-preview: fix leak of IdeEditorView
    
    The html-preview plugin was creating lambda's which held
    references to the various widgetry. These are apparently causing
    leaks. Probably something to be worked out in PyGObject but
    easier for us to just stop using lambda's when possible.

 plugins/html-preview/html_preview.py |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/plugins/html-preview/html_preview.py b/plugins/html-preview/html_preview.py
index 7e7261b..36f95c4 100644
--- a/plugins/html-preview/html_preview.py
+++ b/plugins/html-preview/html_preview.py
@@ -198,7 +198,7 @@ class HtmlPreviewAddin(GObject.Object, Ide.EditorViewAddin):
         group = view.get_action_group('editor-view')
 
         self.action = Gio.SimpleAction(name='preview-as-html', enabled=True)
-        self.action.connect('activate', lambda *_: self.preview_activated(view))
+        self.action.connect('activate', self.preview_activated)
         group.add_action(self.action)
 
         document = view.get_buffer()
@@ -253,9 +253,12 @@ class HtmlPreviewAddin(GObject.Object, Ide.EditorViewAddin):
 
         return sphinx_builddir
 
-    def preview_activated(self, view):
+    def preview_activated(self):
         global can_preview_rst
 
+        if self.view is None:
+            return
+
         if self.lang_id == 'rst':
             if self.sphinx_basedir:
                 if not can_preview_sphinx:
@@ -282,9 +285,9 @@ class HtmlPreviewAddin(GObject.Object, Ide.EditorViewAddin):
         column.add(web_view)
 
         self.action.set_enabled(False)
-        web_view.connect('destroy', lambda *_: self.web_view_destroyed(web_view))
+        web_view.connect('destroy', self.web_view_destroyed)
 
-    def web_view_destroyed(self, web_view):
+    def web_view_destroyed(self, web_view, *args):
         self.action.set_enabled(True)
 
     def search_sphinx_base_dir(self, path):