[meld] Fix some sensitivity handling issues (closes rhbz#835883, rhbz#806489)

[Kai Willadsen <kaiw src gnome org>]

commit b831bb7eb50594a708ab4d9f0fc9ac45ca41cce3
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Dec 16 10:50:42 2012 +1000

    Fix some sensitivity handling issues (closes rhbz#835883, rhbz#806489)
    
    Sensitivity was not being correctly set in cases where no comparison
    pane was focused. This patch corrects two cases: chunk actions when the
    focus pane becomes unset, and merge actions when the focus pane becomes
    unset.

 data/ui/filediff.ui |    3 +++
 meld/filediff.py    |   18 ++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)
---
diff --git a/data/ui/filediff.ui b/data/ui/filediff.ui
index 879f808..cf25b3f 100644
--- a/data/ui/filediff.ui
+++ b/data/ui/filediff.ui
@@ -179,6 +179,7 @@
                         <signal handler="on_textview_button_press_event" name="button_press_event"/>
                         <signal handler="on_textview_expose_event" name="expose_event"/>
                         <signal handler="on_textview_focus_in_event" name="focus_in_event"/>
+                        <signal handler="on_textview_focus_out_event" name="focus_out_event"/>
                         <signal handler="on_key_press_event" name="key_press_event"/>
                         <signal handler="on_key_release_event" name="key_release_event"/>
                         <signal handler="on_textview_popup_menu" name="popup-menu"/>
@@ -254,6 +255,7 @@
                         <signal handler="on_textview_button_press_event" name="button_press_event"/>
                         <signal handler="on_textview_expose_event" name="expose_event"/>
                         <signal handler="on_textview_focus_in_event" name="focus_in_event"/>
+                        <signal handler="on_textview_focus_out_event" name="focus_out_event"/>
                         <signal handler="on_key_press_event" name="key_press_event"/>
                         <signal handler="on_key_release_event" name="key_release_event"/>
                         <signal handler="on_textview_popup_menu" name="popup-menu"/>
@@ -291,6 +293,7 @@
                         <signal handler="on_textview_button_press_event" name="button_press_event"/>
                         <signal handler="on_textview_expose_event" name="expose_event"/>
                         <signal handler="on_textview_focus_in_event" name="focus_in_event"/>
+                        <signal handler="on_textview_focus_out_event" name="focus_out_event"/>
                         <signal handler="on_key_press_event" name="key_press_event"/>
                         <signal handler="on_key_release_event" name="key_release_event"/>
                         <signal handler="on_textview_popup_menu" name="popup-menu"/>
diff --git a/meld/filediff.py b/meld/filediff.py
index b5a45d9..4a3145f 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -401,14 +401,20 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
         self.cursor.line, self.cursor.offset = line, offset
 
     def on_current_diff_changed(self, widget, *args):
-        pane = self.cursor.pane
-        chunk_id = self.cursor.chunk
-        push_left, push_right, pull_left, pull_right, delete, \
-            copy_left, copy_right = (True,) * 7
+        pane = self._get_focused_pane()
+        if pane != -1:
+            # While this *should* be redundant, it's possible for focus pane
+            # and cursor pane to be different in several situations.
+            pane = self.cursor.pane
+            chunk_id = self.cursor.chunk
+
         if pane == -1 or chunk_id is None:
             push_left, push_right, pull_left, pull_right, delete, \
                 copy_left, copy_right = (False,) * 7
         else:
+            push_left, push_right, pull_left, pull_right, delete, \
+                copy_left, copy_right = (True,) * 7
+
             # Push and Delete are active if the current pane has something to
             # act on, and the target pane exists and is editable. Pull is
             # sensitive if the source pane has something to get, and the
@@ -650,6 +656,10 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
         self.on_cursor_position_changed(view.get_buffer(), None, True)
         self._set_merge_action_sensitivity()
 
+    def on_textview_focus_out_event(self, view, event):
+        self.focus_pane = None
+        self._set_merge_action_sensitivity()
+
     def _after_text_modified(self, buffer, startline, sizechange):
         if self.num_panes > 1:
             pane = self.textbuffer.index(buffer)