[meld/ui-next] filediff: Base action sensitivity on the last focused pane

[Kai Willadsen <kaiw src gnome org>]

commit 6573c36e38ef54a7bb40472eb375f5d2de869951
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Mar 2 11:00:36 2019 +1000

    filediff: Base action sensitivity on the last focused pane
    
    This is required for having correct sensitivity for any situation where
    the textviews lose focus while trying to interact with an action e.g.,
    putting actions in a popover.

 meld/filediff.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/meld/filediff.py b/meld/filediff.py
index d95b827c..cb610f0a 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -521,7 +521,11 @@ class FileDiff(Gtk.VBox, MeldDoc):
         self.cursor.line, self.cursor.offset = line, offset
 
     def on_current_diff_changed(self, *args):
-        pane = self._get_focused_pane()
+        try:
+            pane = self.textview.index(self.focus_pane)
+        except ValueError:
+            pane = -1
+
         if pane != -1:
             # While this *should* be redundant, it's possible for focus pane
             # and cursor pane to be different in several situations.