[meld] Make the error helper import and use the toplevel window by default

[Kai Willadsen <kaiw src gnome org>]

commit e0c15bb7c50afd73647c4bd6f31c48956fd77981
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Aug 17 12:48:12 2013 +1000

    Make the error helper import and use the toplevel window by default

 meld/misc.py   |    6 +++++-
 meld/vcview.py |    4 +---
 2 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/meld/misc.py b/meld/misc.py
index 2f3023d..8af8a26 100644
--- a/meld/misc.py
+++ b/meld/misc.py
@@ -50,7 +50,7 @@ def shelljoin( command ):
     return " ".join( [ quote(x) for x in command ] )
 
 
-def error_dialog(primary, secondary, parent, messagetype=gtk.MESSAGE_ERROR):
+def error_dialog(primary, secondary, parent=None, messagetype=gtk.MESSAGE_ERROR):
     """A common error dialog handler for Meld
 
     This should only ever be used as a last resort, and for errors that
@@ -59,6 +59,10 @@ def error_dialog(primary, secondary, parent, messagetype=gtk.MESSAGE_ERROR):
 
     Primary must be plain text. Secondary must be valid markup.
     """
+    if not parent:
+        from meld.meldapp import app
+        parent = app.window.widget
+
     dialog = gtk.MessageDialog(
         parent=parent,
         flags=gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT,
diff --git a/meld/vcview.py b/meld/vcview.py
index 4ae10fe..7f530a2 100644
--- a/meld/vcview.py
+++ b/meld/vcview.py
@@ -41,7 +41,6 @@ from .ui import gnomeglade
 from .ui import vcdialogs
 from meld.vc import _null
 
-from meld.meldapp import app
 
 def _commonprefix(files):
     if len(files) != 1:
@@ -744,8 +743,7 @@ class VcView(melddoc.MeldDoc, gnomeglade.Component):
                 gfile = gio.File(name)
                 gfile.trash()
             except gio.Error as e:
-                misc.error_dialog(_("Error removing %s") % name, str(e),
-                                  parent=app.window.widget)
+                misc.error_dialog(_("Error removing %s") % name, str(e))
         workdir = _commonprefix(files)
         self.refresh_partial(workdir)