=== modified file 'src/alloc.c'
--- src/alloc.c	2012-05-25 18:19:24 +0000
+++ src/alloc.c	2012-05-28 11:18:45 +0000
@@ -3211,6 +3211,9 @@
 
   MALLOC_BLOCK_INPUT;
 
+  if (!NULL_INTERVAL_P (STRING_INTERVALS (name)))
+    name = build_string (SDATA (name));
+
   if (symbol_free_list)
     {
       XSETSYMBOL (val, symbol_free_list);
@@ -5691,7 +5694,9 @@
 	  }
 	if (!PURE_POINTER_P (XSTRING (ptr->xname)))
 	  MARK_STRING (XSTRING (ptr->xname));
-	MARK_INTERVAL_TREE (STRING_INTERVALS (ptr->xname));
+
+	/* Symbol name should have no properties.  */
+	eassert (NULL_INTERVAL_P (STRING_INTERVALS (ptr->xname)));
 
 	ptr = ptr->next;
 	if (ptr)