symbol.gc.bug

[Eric Wong]

diff --git a/symbol.c b/symbol.c
index 630a386..bf05634 100644
--- a/symbol.c
+++ b/symbol.c
@@ -458,7 +458,10 @@ dsymbol_pindown(VALUE sym)
 
     if (UNLIKELY(SYMBOL_PINNED_P(sym) == 0)) {
        VALUE fstr = RSYMBOL(sym)->fstr;
-       sym = dsymbol_check(sym);
+
+       if (UNLIKELY(rb_objspace_garbage_object_p(sym))) {
+           rb_bug("attempted to pindown garbage sym");
+       }
        FL_SET(sym, SYMBOL_PINNED);
 
        /* make it permanent object */
@@ -525,6 +528,9 @@ rb_intern_cstr_without_pindown(const char *name, long len, 
rb_encoding *enc)
     OBJ_FREEZE(str);
 
     if (st_lookup(global_symbols.str_id, str, &id)) {
+       if (ID_DYNAMIC_SYM_P((ID)id)) {
+           return (ID)dsymbol_check((VALUE)id);
+       }
        return (ID)id;
     }