[meld] filediff: Improve revert dialog file list display

[Kai Willadsen <kaiw src gnome org>]

commit 9ecd1d60d5e2f9ccf55621deebdbd5e32119634b
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Fri Feb 9 06:38:12 2018 +1000

    filediff: Improve revert dialog file list display
    
    Two changes here: firstly to use the message dialog area that *is* now
    available; and secondly to use unicode list bullets.

 data/ui/filediff.ui |  3 +--
 meld/filediff.py    | 11 +++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)
---
diff --git a/data/ui/filediff.ui b/data/ui/filediff.ui
index 39f3454a..3532b3e2 100644
--- a/data/ui/filediff.ui
+++ b/data/ui/filediff.ui
@@ -834,8 +834,7 @@
     <property name="skip_taskbar_hint">True</property>
     <property name="message_type">question</property>
     <property name="text" translatable="yes">Revert unsaved changes to documents?</property>
-    <property name="secondary_text" translatable="yes">Changes made to the following documents will be 
permanently lost:
-</property>
+    <property name="secondary_text" translatable="yes">Changes made to the following documents will be 
permanently lost:</property>
     <child internal-child="vbox">
       <object class="GtkBox" id="dialog-vbox2">
         <property name="visible">True</property>
diff --git a/meld/filediff.py b/meld/filediff.py
index c349a376..4405b0ff 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -1711,10 +1711,13 @@ class FileDiff(MeldDoc, Component):
 
         dialog = Component("filediff.ui", "revert_dialog")
         dialog.widget.set_transient_for(self.widget.get_toplevel())
-        # FIXME: Should be packed into dialog.widget.get_message_area(),
-        # but this is unbound on currently required PyGTK.
-        filelist = "\n".join(["\t" + f for f in unsaved])
-        dialog.widget.props.secondary_text += filelist
+
+        filelist = Gtk.Label("\n".join(["\t• " + f for f in unsaved]))
+        filelist.props.xalign = 0.0
+        filelist.show()
+        message_area = dialog.widget.get_message_area()
+        message_area.pack_start(filelist, expand=False, fill=True, padding=0)
+
         response = dialog.widget.run()
         dialog.widget.destroy()
         return response == Gtk.ResponseType.OK