[gnome-taquin] Add a security.

[Arnaud B. <arnaudb src gnome org>]

commit 309cb65ed008f057cd276ea3971be642f44697d0
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Feb 18 14:58:46 2019 +0100

    Add a security.
    
    Use an infinity sign when too
    much moves have been done. It
    should normally never happen.

 src/game-headerbar.vala | 14 ++++++++++++--
 src/taquin-game.vala    | 20 ++++++++++++++++----
 2 files changed, 28 insertions(+), 6 deletions(-)
---
diff --git a/src/game-headerbar.vala b/src/game-headerbar.vala
index 52eb7db..71e6b07 100644
--- a/src/game-headerbar.vala
+++ b/src/game-headerbar.vala
@@ -158,7 +158,7 @@ private class GameHeaderBar : BaseHeaderBar
     private uint last_moves_count = 0;
     internal void set_moves_count (ref uint moves_count)
     {
-        history_button.set_label (moves_count.to_string ());
+        history_button.set_label (get_moves_count_string (ref moves_count));
         history_button.set_sensitive ((moves_count != 0) || (best_score != 0));
         last_moves_count = moves_count;
     }
@@ -297,9 +297,19 @@ private class GameHeaderBar : BaseHeaderBar
         GLib.Menu section = new GLib.Menu ();
 
         /* Translators: during a game that has already been finished (and possibly restarted), entry in the 
menu of the moves button */
-        section.append (_("Best score: %u").printf (best_score), null);
+        section.append (_("Best score: %s").printf (get_moves_count_string (ref best_score)), null);
 
         section.freeze ();
         menu.append_section (null, section);
     }
+
+    private static string get_moves_count_string (ref uint moves_count)
+    {
+        string moves_count_string;
+        if (moves_count != uint.MAX)
+            moves_count_string = moves_count.to_string ();
+        else
+            moves_count_string = "∞";
+        return moves_count_string;
+    }
 }
diff --git a/src/taquin-game.vala b/src/taquin-game.vala
index df12d63..599e3e6 100644
--- a/src/taquin-game.vala
+++ b/src/taquin-game.vala
@@ -188,11 +188,17 @@ private class Game : Object
         int8 move_number = move_x_axis ? x_gap - x : y_gap - y;
 
         if (undoing)
-            moves_count--;
+        {
+            if (moves_count == 0)
+                assert_not_reached ();
+            if (moves_count != uint.MAX)
+                moves_count--;
+        }
         else
         {
             add_move (/* move_x_axis, move_number,*/ x_gap, y_gap);
-            moves_count++;
+            if (moves_count != uint.MAX)
+                moves_count++;
         }
 
         if (move_x_axis)
@@ -278,11 +284,17 @@ private class Game : Object
         }
 
         if (undoing)
-            moves_count--;
+        {
+            if (moves_count == 0)
+                assert_not_reached ();
+            if (moves_count != uint.MAX)
+                moves_count--;
+        }
         else
         {
             add_move (move_x_axis ? (new_coord == 0 ? -1 : size) : x, move_x_axis ? y : (new_coord == 0 ? -1 
: size));
-            moves_count++;
+            if (moves_count != uint.MAX)
+                moves_count++;
         }
 
         move (move_x_axis,