--- Compress-LZF/LZF.xs	2001/09/27 19:51:26	1.3
+++ Compress-LZF/LZF.xs	2002/03/03 04:45:18	1.9
@@ -21,8 +21,11 @@
 #define MAGIC_LO	0
 #define MAGIC_U		0 /* uncompressed data follows */
 #define MAGIC_C		1 /* compressed data follows */
-#define MAGIC_R		4 /* storable (reference, freeze) */
+#define MAGIC_undef	2 /* the special value undef */
 #define MAGIC_CR	3 /* storable (reference, freeze), compressed */
+#define MAGIC_R		4 /* storable (reference, freeze) */
+#define MAGIC_CR_deref	5 /* storable (NO reference, freeze), compressed */
+#define MAGIC_R_deref	6 /* storable NO (reference, freeze) */
 #define MAGIC_HI	7 /* room for one higher storable major */
 
 #define IN_RANGE(v,l,h) ((unsigned int)((unsigned)(v) - (unsigned)(l)) <= (unsigned)(h) - (unsigned)(l))
@@ -225,13 +228,20 @@
         PROTOTYPE: $
         PPCODE:
 
-        if (SvTYPE(sv) != SVt_IV
+        if (!SvOK (sv))
+          XPUSHs (sv_2mortal (newSVpvn ("\02", 1))); /* 02 == MAGIC_undef */
+        else if (SvTYPE(sv) != SVt_IV
             && SvTYPE(sv) != SVt_NV
             && SvTYPE(sv) != SVt_PV) /* mstore */
           {
+            int deref = !SvROK (sv);
+
             if (!storable_mstore)
               need_storable ();
 
+            if (deref)
+              sv = newRV_noinc (sv);
+
             PUSHMARK (SP);
             XPUSHs (sv);
             PUTBACK;
@@ -247,11 +257,16 @@
               croak ("Storable format changed, need newer version of Compress::LZF");
 
             if (ix) /* compress */
-              XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_CR, 0)));
+              XPUSHs (sv_2mortal (compress_sv (sv, deref ? MAGIC_CR_deref : MAGIC_CR, 0)));
             else
-              XPUSHs (sv);
+              {
+                if (deref)
+                  SvPVX (sv)[0] = MAGIC_R_deref;
+
+                XPUSHs (sv);
+              }
           }
-        else if (IN_RANGE (SvPVX (sv)[0], MAGIC_LO, MAGIC_HI))
+        else if (sv && IN_RANGE (SvPVX (sv)[0], MAGIC_LO, MAGIC_HI))
           XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, 1))); /* need to prefix only */
         else if (ix == 2) /* compress always */
           XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, 0)));
@@ -263,12 +278,18 @@
 	SV *	sv
         PROTOTYPE: $
         PPCODE:
-        char hdr = SvPVX (sv)[0];
 
-        if (IN_RANGE (hdr, MAGIC_LO, MAGIC_HI))
+        int deref = 0;
+
+        SvGETMAGIC (sv);
+        if (SvPOK (sv) && IN_RANGE (SvPV_nolen (sv)[0], MAGIC_LO, MAGIC_HI))
           {
             switch (SvPVX (sv)[0])
               {
+                case MAGIC_undef:
+                  XPUSHs (sv_2mortal (NEWSV (0, 0)));
+                  break;
+
                 case MAGIC_U:
                   XPUSHs (sv_2mortal (decompress_sv (sv, 0)));
                   break;
@@ -277,8 +298,16 @@
                   XPUSHs (sv_2mortal (decompress_sv (sv, 1)));
                   break;
 
+                case MAGIC_CR_deref:
+                  deref = 1;
                 case MAGIC_CR:
                   sv = sv_2mortal (decompress_sv (sv, 1)); /* mortal could be optimized */
+                case MAGIC_R_deref:
+                  if (SvPVX (sv)[0] == MAGIC_R_deref)
+                    {
+                      deref = 1;
+                      SvPVX (sv)[0] = MAGIC_R;
+                    }
                 case MAGIC_R:
                   if (!storable_mstore)
                     need_storable ();
@@ -292,7 +321,18 @@
 
                   SPAGAIN;
 
-                  /*XPUSHs (POPs);*/
+                  if (deref)
+                    {
+                      SV *ref = SvREFCNT_inc (SvRV (TOPs));
+
+                      SvREFCNT_dec (TOPs); /* destroy superfluous ref */
+                      SETs (ref);
+
+                      if (SvPVX (sv)[0] == MAGIC_R)
+                        SvPVX (sv)[0] = MAGIC_R;
+                    }
+
+                  XPUSHs (POPs); /* this is a nop, hopefully */
 
                   break;