[meld] meldapp: Improve some error case logic when creating tabs

[Kai Willadsen <kaiw src gnome org>]

commit 74237081b852dda3dc31bd1f865f771f6bd989b8
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Tue May 20 07:22:08 2014 +1000

    meldapp: Improve some error case logic when creating tabs

 meld/meldapp.py |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/meld/meldapp.py b/meld/meldapp.py
index 1069835..c7a6d87 100644
--- a/meld/meldapp.py
+++ b/meld/meldapp.py
@@ -16,6 +16,7 @@
 
 from __future__ import print_function
 
+import logging
 import optparse
 import os
 import StringIO
@@ -31,6 +32,8 @@ import meld.ui.util
 
 from meld.conf import _
 
+log = logging.getLogger(__name__)
+
 
 class MeldApp(Gtk.Application):
 
@@ -139,6 +142,7 @@ class MeldApp(Gtk.Application):
             window = self.get_meld_window()
         else:
             window = self.new_window()
+
         return window.open_paths(paths, **kwargs)
 
     def diff_files_callback(self, option, opt_str, value, parser):
@@ -291,6 +295,7 @@ class MeldApp(Gtk.Application):
                 return parser.exit_status
             return tab
 
+        tab = None
         error = None
         comparisons = options.diff + [args]
         options.newtab = options.newtab or not command_line.get_is_remote()
@@ -310,7 +315,8 @@ class MeldApp(Gtk.Application):
                 tab.set_merge_output_file(options.outfile)
 
         if error:
-            if not self.get_meld_window().has_pages():
+            log.debug("Couldn't open comparison: %s", error)
+            if not tab:
                 parser.local_error(error)
             else:
                 print(error)