--- search.c	2006-11-29 16:02:21.000000000 -0500
+++ search.c	2009-11-11 17:39:41.000000000 -0500
@@ -229,11 +229,11 @@
 	/* Get offset of first entry.  Then eliminate duplicates
 	   and get offsets of unique strings. */
 
-	if (strings[0][0] != NULL)
+	if (strings[0][0] != '\0')
 	    offsets[0] = index_lookup(strings[0], dbase);
 
 	for (i = 1; i < MAX_FORMS; i++)
-	    if ((strings[i][0]) != NULL && (strcmp(strings[0], strings[i])))
+	    if ((strings[i][0]) != '\0' && (strcmp(strings[0], strings[i])))
 		offsets[i] = index_lookup(strings[i], dbase);
     }
 
@@ -492,9 +492,11 @@
 	while(cursyn) {
 	    if (cursyn->nextform)
 		free_syns(cursyn->nextform);
+	    cursyn->nextform = NULL;
 	    nextsyn = cursyn->nextss;
 	    free_synset(cursyn);
 	    cursyn = nextsyn;
+	    nextsyn = NULL;
 	}
     }
 }
@@ -504,32 +506,64 @@
 void free_synset(SynsetPtr synptr)
 {
     int i;
-    
-    free(synptr->pos);
+   
+    if (synptr->pos) 
+	free(synptr->pos);
+    synptr->pos = NULL;
     for (i = 0; i < synptr->wcount; i++){
-	free(synptr->words[i]);
+	if (!synptr->words)
+		break;
+	if (synptr->words[i]) {
+		free(synptr->words[i]);
+		synptr->words[i] = NULL;
+	}
     }
-    free(synptr->words);
-    free(synptr->wnsns);
-    free(synptr->lexid);
+    if (synptr->words)
+	    free(synptr->words);
+    synptr->words = NULL;
+    if (synptr->wnsns)
+	    free(synptr->wnsns);
+    synptr->wnsns = NULL;
+    if (synptr->lexid)
+	    free(synptr->lexid);
+    synptr->lexid = NULL;
     if (synptr->ptrcount) {
-	free(synptr->ptrtyp);
-	free(synptr->ptroff);
-	free(synptr->ppos);
-	free(synptr->pto);
-	free(synptr->pfrm);
+	if (synptr->ptrtyp)
+		free(synptr->ptrtyp);
+	synptr->ptrtyp = NULL;
+	if (synptr->ptroff)
+		free(synptr->ptroff);
+	synptr->ptroff = NULL;
+	if (synptr->ppos)
+		free(synptr->ppos);
+	synptr->ppos = NULL;
+	if (synptr->pto)
+		free(synptr->pto);
+	synptr->pto = NULL;
+	if (synptr->pfrm)
+		free(synptr->pfrm);
+	synptr->pfrm = NULL;
     }
     if (synptr->fcount) {
-	free(synptr->frmid);
-	free(synptr->frmto);
+	if (synptr->frmid)
+		free(synptr->frmid);
+	synptr->frmid = NULL;
+	if (synptr->frmto)
+		free(synptr->frmto);
+	synptr->frmto = NULL;
     }
     if (synptr->defn)
 	free(synptr->defn);
+    synptr->defn = NULL;
     if (synptr->headword)
 	free(synptr->headword);
+    synptr->headword = NULL;
     if (synptr->ptrlist)
 	free_syns(synptr->ptrlist); /* changed from free_synset() */
-    free(synptr);
+    synptr->ptrlist = NULL;
+    synptr->nextss = NULL;
+    free(synptr);	
+    synptr = NULL;
 }
 
 /* Free an index structure */
@@ -1658,7 +1692,8 @@
 	if (ptrtyp == COORDS) {	/* clean up by removing hypernym */
 	    lastsyn = synlist->ptrlist;
 	    synlist->ptrlist = lastsyn->ptrlist;
-	    free_synset(lastsyn);
+	    lastsyn->ptrlist = NULL;
+	    free_syns(lastsyn);
 	}
     }
     wnresults.searchds = synlist;