[gnome-mines] Never pause the game before it has begun

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ad69a8b1bdc8345d0d04b4deacd2f1b5e7190e69
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Tue Apr 15 18:34:09 2014 -0500

    Never pause the game before it has begun
    
    Clicking outside the window incorrectly results in the New Game button
    being replaced with the Play button, which both pauses and resumes the
    game. Oops.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=728305

 src/gnome-mines.vala |    2 +-
 src/minefield.vala   |    5 +++++
 2 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/src/gnome-mines.vala b/src/gnome-mines.vala
index 5f77e6e..d00ebe3 100644
--- a/src/gnome-mines.vala
+++ b/src/gnome-mines.vala
@@ -358,7 +358,7 @@ public class Mines : Gtk.Application
 
     private bool window_focus_out_event_cb (Gdk.EventFocus event)
     {
-        if (minefield != null)
+        if (minefield != null && minefield.is_clock_started ())
             minefield.paused = true;
 
         return false;
diff --git a/src/minefield.vala b/src/minefield.vala
index 505c7aa..edf5396 100644
--- a/src/minefield.vala
+++ b/src/minefield.vala
@@ -146,6 +146,11 @@ public class Minefield
         this.height = height;
         this.n_mines = n_mines;
     }
+
+    public bool is_clock_started ()
+    {
+        return elapsed > 0;
+    }
    
     public bool has_mine (uint x, uint y)
     {