[gnome-builder] html preview: disconnect 'changed' on webview closing

[Sébastien Lafargue <slafargue src gnome org>]

commit f254a9795e369d9c3d177b29c69c67a3413e6c5c
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Sun Mar 26 16:32:16 2017 +0200

    html preview: disconnect 'changed' on webview closing

 .../html-preview/html_preview_plugin/__init__.py   |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/plugins/html-preview/html_preview_plugin/__init__.py 
b/plugins/html-preview/html_preview_plugin/__init__.py
index bd8fc7c..9d47953 100644
--- a/plugins/html-preview/html_preview_plugin/__init__.py
+++ b/plugins/html-preview/html_preview_plugin/__init__.py
@@ -354,8 +354,12 @@ class HtmlPreviewView(Ide.LayoutView):
                 self.rst = True
 
         document.connect('changed', self.on_changed)
+        self.webview.connect('destroy', self.web_view_destroyed)
         self.on_changed(document)
 
+    def web_view_destroyed(self, web_view):
+        self.document.disconnect_by_func(self.on_changed)
+
     def do_get_title(self):
         title = self.document.get_title()
         return '%s (Preview)' % title