--- deliantra/server/include/shstr.h	2006/09/03 00:18:41	1.5
+++ deliantra/server/include/shstr.h	2006/09/03 23:33:01	1.8
@@ -1,68 +1,88 @@
 #ifndef SHSTR_H__
 #define SHSTR_H__
 
-extern int buf_overflow(const char *buf1, const char *buf2, int bufsize);
+#include "util.h"
+
+extern int buf_overflow (const char *buf1, const char *buf2, int bufsize);
 
 struct shstr
 {
+  static const char *null;
+
   const char *s;
 
-  int &refcnt ()
+  static int &refcnt (const char *s)
   {
     return *((int *)s - 1);
   }
 
+  static int &length (const char *s)
+  {
+    return *((int *)s - 2);
+  }
+
+  int &refcnt () const
+  {
+    return refcnt (s);
+  }
+
+  int length () const
+  {
+    return length (s);
+  }
+
   static const char *find (const char *s);
   static const char *intern (const char *s);
 
   static void gc (); // garbage collect a few strings
 
-  // this is used for informational messages and the like I/O
-  const char *operator &() const { return s ? s : "<nil>"; }
-
-  const char &operator [](int i) { return s[i]; }
-  operator const char *() const { return s; }
+  // this is used for informational messages and the like
+  const char *operator &() const { return s; }
 
-  int length () const
-  {
-    return s ? *((int *)s - 2) : 0;
-  }
+  const char &operator [](int i) const { return s[i]; }
+  operator const char *() const { return s == null ? 0 : s; }
 
   shstr ()
-  : s (0)
+  : s (null)
   {
   }
 
-  shstr (shstr &sh)
+  shstr (const shstr &sh)
   : s (sh.s)
   {
-    if (s) ++refcnt ();
+    ++refcnt ();
   }
 
   explicit shstr (const char *s)
   : s (intern (s))
   {
-    if (s) ++refcnt ();
   }
 
   ~shstr ()
   {
-    if (s) --refcnt ();
+    --refcnt ();
   }
 
   const shstr &operator =(const shstr &sh)
   {
-    if (s) --refcnt ();
+    --refcnt ();
     s = sh.s;
-    if (s) ++refcnt ();
+    ++refcnt ();
 
     return *this;
   }
 
   const shstr &operator =(const char *str)
   {
-    if (s) --refcnt ();
-    s = intern (str);
+    --refcnt ();
+
+#if 0
+    // this optimises the important case of str == constant 0
+    if (is_constant (str))
+      s = str ? intern (str) : null;
+    else
+#endif
+      s = intern (str);
 
     return *this;
   }