[meld] Further future compat adjusted from 2to3

[Kai Willadsen <kaiw src gnome org>]

commit 7c7ea81040368a824becd1a2b4f2f29b61e4f16c
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Oct 27 12:40:09 2012 +1000

    Further future compat adjusted from 2to3

 meld/meldbuffer.py    |    2 +-
 meld/meldwindow.py    |    3 ++-
 meld/ui/gnomeglade.py |    2 +-
 meld/util/compat.py   |    1 +
 meld/util/prefs.py    |    9 ++++++---
 5 files changed, 11 insertions(+), 6 deletions(-)
---
diff --git a/meld/meldbuffer.py b/meld/meldbuffer.py
index e23c817..b7e9f3c 100644
--- a/meld/meldbuffer.py
+++ b/meld/meldbuffer.py
@@ -133,7 +133,7 @@ class BufferLines(object):
             lines.append("")
             ends.append("")
 
-        hi = self.buf.get_line_count() if hi == sys.maxint else hi
+        hi = self.buf.get_line_count() if hi == sys.maxsize else hi
         if hi - lo != len(lines):
             # These codepoints are considered line breaks by Python, but not
             # by GtkTextStore.
diff --git a/meld/meldwindow.py b/meld/meldwindow.py
index c4d0ea2..1bd6d38 100644
--- a/meld/meldwindow.py
+++ b/meld/meldwindow.py
@@ -34,6 +34,7 @@ from . import vcview
 from .ui import gnomeglade
 from .ui import notebooklabel
 
+from .util.compat import string_types
 from .util.sourceviewer import srcviewer
 from .meldapp import app
 
@@ -256,7 +257,7 @@ class MeldWindow(gnomeglade.Component):
 
     def on_idle(self):
         ret = self.scheduler.iteration()
-        if ret and isinstance(ret, basestring):
+        if ret and isinstance(ret, string_types):
             self.statusbar.set_task_status(ret)
 
         pending = self.scheduler.tasks_pending()
diff --git a/meld/ui/gnomeglade.py b/meld/ui/gnomeglade.py
index d7b3f2b..181cecc 100644
--- a/meld/ui/gnomeglade.py
+++ b/meld/ui/gnomeglade.py
@@ -93,7 +93,7 @@ def connect_signal_handlers(obj):
         if match:
             when, widgetname, signal = match.groups()
             method = getattr(obj, attr)
-            assert callable(method)
+            assert hasattr(method, '__call__')
             try:
                 widget = getattr(obj, widgetname)
             except AttributeError:
diff --git a/meld/util/compat.py b/meld/util/compat.py
index bd580f0..5bff563 100644
--- a/meld/util/compat.py
+++ b/meld/util/compat.py
@@ -3,3 +3,4 @@ import sys
 
 # Python 2/3 compatibility, named as per six
 text_type = str if sys.version_info[0] == 3 else unicode
+string_types = str if sys.version_info[0] == 3 else basestring
diff --git a/meld/util/prefs.py b/meld/util/prefs.py
index 46a8bce..9867e47 100644
--- a/meld/util/prefs.py
+++ b/meld/util/prefs.py
@@ -177,7 +177,7 @@ class ConfigParserPreferences(object):
         rootkey : unused (retained for compatibility with existing gconf API)
         initial : a dictionary of string to Value objects.
         """
-        self.__dict__["_parser"] = ConfigParser.SafeConfigParser()
+        self.__dict__["_parser"] = configparser.SafeConfigParser()
         self.__dict__["_listeners"] = []
         self.__dict__["_prefs"] = initial
         self.__dict__["_type_mappings"] = {
@@ -269,10 +269,13 @@ class ConfigParserPreferences(object):
         return "\n".join(prefs_entries)
 
 
-# Prefer gconf, falling back to ConfigParser
+# Prefer gconf, falling back to configparser
 try:
     import gconf
     Preferences = GConfPreferences
 except ImportError:
-    import ConfigParser
+    try:
+        import configparser
+    except ImportError:
+        import ConfigParser as configparser
     Preferences = ConfigParserPreferences