*** empty log message ***

diff --git a/MSymbol.cs b/MSymbol.cs
index b92bcbf..96ff477 100644 (file)
--- a/MSymbol.cs
+++ b/MSymbol.cs
@@ -53,26 +53,30 @@ namespace M17N.Core
       return str;
     }
 
-    public override bool Equals (object sym)
+    public static bool operator== (MSymbol sym1, MSymbol sym2)
     {
-      if (sym == null)
-       return false;
-      return (this.data == ((MSymbol) sym).data);
+      if (System.Object.ReferenceEquals(sym1, sym2))
+        return true;
+      if (((object) sym1 == null) || ((object) sym2 == null))
+        return false;
+      return sym1.data == sym2.data;
     }
 
-    public override int GetHashCode ()
+    public static bool operator!= (MSymbol sym1, MSymbol sym2)
     {
-      return (data.name.GetHashCode ());
+      return ! (sym1 == sym2);
     }
 
-    public static bool operator== (MSymbol sym1, MSymbol sym2)
+    public override bool Equals (object sym)
     {
-      return (sym1.data == sym2.data);
+      if (sym == null)
+       return false;
+      return (this.data == ((MSymbol) sym).data);
     }
 
-    public static bool operator!= (MSymbol sym1, MSymbol sym2)
+    public override int GetHashCode ()
     {
-      return (sym1.data != sym2.data);
+      return (data.name.GetHashCode ());
     }
 
     public MPlist Find (MSymbol key)